So far, Weiser has filed 33 lawsuits against the Trump Administration in partnership with other attorneys general across the country. Weiser’s lawsuits focus on maintaining Colorado’s federal funding and protecting the rights of Colorado citizens.
The separation of powers is a common theme of Weiser’s lawsuits, including his objection to Trump’s tariff policy.
“My question to this administration is: is nothing sacred?” Weiser said in April. “Is nothing worth protecting?”
Weiser hasn't let up since, sometimes filing multiple lawsuits on the same day. Here are all the lawsuits that Colorado, under the direction of the AG's office, has filed against the Trump administration.
January 21: Upholding Birthright Citizenship
In response to Trump’s executive order repealing birthright citizenship filed the day he took office, Weiser joined nineteen other states and cities in suing to invalidate the order. The lawsuit argued that birthright citizenship has existed in the United States for centuries and been upheld by the Supreme Court twice since the Fourteenth Amendment was ratified in 1868. Multiple judges have since blocked enforcement of the executive order as the legal challenge makes its way through court.
January 28: Objecting to Federal Funding Freezes
On January 27, the Trump administration moved to withhold trillions of dollars in federal funds from states, research groups and nonprofits. Weiser joined a coalition of attorneys general to file a lawsuit on January 28, objecting to the funding freezes on the grounds that the executive branch cannot take back funding appropriated by Congress. Two days later, a U.S. District Court judge blocked the funding freezes until the court could make a more permanent decision. On February 28, the coalition specifically sued again over freezes to Federal Emergency Management Agency (FEMA) funds.
On March 6, U.S. District Court Judge John McConnell Jr. ordered the release of all the federal funds in question, requiring proof that the FEMA funds had been unfrozen by March 14.
February 7: Keeping DOGE Out of Private Data
On February 2, the U.S. Treasury Department issued a new policy allowing members of the Department of Government Efficiency (DOGE) to access the Treasury’s central payment system. Usually, that payment system can only be accessed by limited career civil servants as it contains access to Social Security payments, veterans' benefits and Medicare and Medicaid payments, among other private information.
Along with Weiser, eighteen other attorneys general sued, arguing that the new policy violates the law governing who can access the central payment system. The group asked for an injunction prohibiting expanded access to the system. On February 14, a judge in New York granted a temporary order blocking DOGE access to the system.
February 10: Challenging Cuts to Medical Research
After the Trump administration announced cuts to indirect cost reimbursements at every research institution throughout the country, Weiser and other attorneys general sued the Trump administration, the U.S. Department of Health and Human Services, and the National Institutes of Health. Indirect cost reimbursements cover lab, faculty, infrastructure and utility costs to conduct biomedical research. Without the reimbursements, necessary medical research could be put to an end, according to the lawsuit.
According to Weiser’s office, the cuts would eliminate nearly $90 million in funding across Colorado State University, the University of Colorado Anschutz Medical Campus and the University of Colorado, Boulder.
On March 5, a federal district court judge blocked the cuts with a preliminary injunction.
February 19: Maintaining Gender-Affirming Care
When Trump threatened to cut funding to institutions and prosecute medical professionals for providing gender-affirming care in an executive order, the University of Colorado Anschutz Medical Campus stopped providing puberty-delaying medications and hormone therapies to patients. Denver Health and Children’s Hospital Colorado also rolled back gender-affirming care programs. On February 19, Weiser joined a lawsuit originally filed by the state of Washington seeking to block the executive order.
"Gender-affirming care is legally protected health care in Colorado, and with this lawsuit, Colorado hospitals will again be free to provide critical care,” Weiser said in an announcement after joining the lawsuit.
The lawsuit argued the executive order violates the principles of equal protection under the Constitution as the order singled out transgender people. A U.S. District Court of Washington judge quickly agreed that the order “blatantly discriminated” against transgender youth. By January 20, Denver Health and Children’s Hospital Colorado both announced they would reinstate components of their previous gender-affirming care policies.
March 6: Saving Teacher Preparation Grants
Because there is a shortage of teachers across the country, Congress established the Teacher Quality Partnership and Supporting Effective Educator Development grant programs to help train and recruit teachers. The Trump administration attempted to terminate $600 million in grant funding allocated to those programs. According to Weiser’s office, the cuts included $2.8 million for a Colorado program dedicated to solving the teacher shortage in rural parts of the state.
Weiser and a coalition of other attorneys general sued to block the termination of the funding, arguing the administration did not have the authority to do so. On March 10, a Massachusetts judge granted the group a temporary restraining order reinstating the grant program after determining there was no reasonable explanation given for why the grants were being cut.
However, the Supreme Court reversed the Massachusetts ruling, allowing the grant funding to remain frozen while the case plays out.
President Donald Trump's administration has pushed federal cuts and threatened to withhold funding for several Colorado state programs in 2025.
Evan Semón
March 6: Opposing Federal Layoffs
March 6 was a busy day for Weiser: after opposing Trump's grant withholding, the state AG's office sued the Trump administration for laying off probational federal employees illegally.
The lawsuit argued that proper procedure wasn't followed when the administration laid off thousands of federal employees. Employees are meant to be given sixty days' notice and information about how to apply for unemployment benefits. Additionally, if more than fifty federal employees in a state are fired, the federal government is required to notify the state. The Trump Administration did not comply with either regulation, according to the lawsuit.
In April, a Maryland judge ordered the Trump administration to reinstate probationary federal employees who had been laid off.
March 13: Preserving the U.S. Department of Education
On March 11, the Trump administration announced a shutdown of the U.S. Department of Education. Weiser and twenty other attorneys general sued to preserve the department, arguing the destruction of the agency would hurt millions of students across the country.
Colorado specifically received over $1.2 billion from the federal government for school-related programs, Weiser added in his announcement of the lawsuit.
“This evisceration of the agency will harm Coloradans, undermine our education system, and create chaos,” Weiser said. “It is plainly unconstitutional, as only Congress can lawfully dismantle the department that it created or shut down services it has required the federal government to fund.”
The coalition sought a court order to stop the administration from cutting the department’s workforce and thereby dismantling the DOE. On May 22, a Massachusetts judge issued a preliminary injunction prohibiting the shutdown of the DOE and ordering any employees who had been fired to be reinstated. However, the Supreme Court reversed that decision on July 14, allowing the cuts to move forward.
April 1: Suing RFK Jr. For Terminating Public Health Grants
When HHS Secretary Robert F. Kennedy Jr. announced cuts to $11 billion in grant funding for programs aimed to improve public health on March 24, Kennedy said the cuts came because the COVID-19 pandemic is over.
Weiser and other AGs quickly replied, arguing that the grant terminations were made in error as the government had actually declared the pandemic over a year ago and Congress had still appropriated the grant funds. According to Weiser, Colorado could lose over $229 million from the grant cancellations. The lawsuit asked for a temporary restraining order preventing the cuts. On June 16, a federal judge ordered that the grants be reinstated and ruled that the terminations were illegal in the first place.
April 3: Safeguarding Election Processes
Last month, Trump, in partnership with U.S. Attorney General Pam Bondi, announced sweeping changes to elections that would restrict voting by requiring documentary proof of citizenship when people register to vote and requiring states to change their mail-in voting procedures.
Weiser and nineteen other attorneys general sued, arguing the order is unconstitutional because the Constitution specifically grants the oversight of elections to states rather than the federal government.
Colorado is known for having an excellent election system, which Weiser cited in his announcement of the lawsuit.
“This election's executive order is an overreach by the White House and it threatens to undermine Colorado’s well-established gold standard for free and fair elections,” he said.
The lawsuit asks a judge to rule that several provisions of the executive order are unconstitutional, and to block them from being implemented. For now, a Massachusetts judge has issued a preliminary injunction blocking many provisions of Trump's executive order, ruling that the executive branch cannot require documentary proof of citizenship or change how states handle mail-in voting.
April 4: Calling Out the Feds for Stalling Grant Reviews for Medical Research
Weiser, along with fifteen other state attorneys general, filed a lawsuit against RFK and federal health agencies for delaying grant funding for medical research by dragging their feet on the grant review process. According to the lawsuit, the NIH has cancelled meetings of the two groups that usually review grants, effectively blocking billions of dollars worth of medical research. The lawsuit asks the U.S. District Court of Massachusetts to require the NIH to resume the regular process of grant review.
In June, the Massachusetts court ruled in favor of the plaintiffs, saying the delays and revoked grants were "arbitrary and capricious." The Trump administration is appealing the decision.
April 4: Supporting Libraries, Museums and Minority-Owned Businesses
On the same day he sued for blocking medical research, Weiser joined a lawsuit opposing a Trump executive order that would dismantle the Institute of Museum and Library Services and the Minority Business Development Agency. The order would also shutter the Federal Mediation and Conciliation Service, which helps resolve labor disputes.
According to Weiser, History Colorado — the state history museum — could lose over $330,000 in promised federal funding. Like many previous Weiser lawsuits, the case asserts that the president can’t cut funding to federal agencies because that power rests with Congress. In May, a judge in Rhode Island issued a preliminary injunction preventing the executive order from taking effect.
April 23: Preventing Trump Tariffs
The Trump administration is imposing sweeping tariffs on most countries in the world, including 25 percent tariffs on Canada and Mexico, America’s top trading partners. But if thirteen attorneys general, including Weiser, have their way, those tariffs will be reversed.
The group filed a lawsuit arguing only Congress has the power to impose tariffs and that the Trump administration hasn’t shown that there is an “unusual and extraordinary threat”, which is required if the president is to step in and make a decision on tariffs. No president has ever done so, the lawsuit adds.
At the end of May, a U.S. Court of International Trade judge blocked Trump's move to implement tariffs without authorization from Congress. Since then, Trump has challenged that ruling and is currently able to levy tariffs. The Supreme Court heard arguments in the case at the end of July.
April 27: Upholding Civil Rights in Education
On April 3, the U.S. DOE issued a new interpretation of Title VI of the Civil Rights Act regarding diversity, equity and inclusion. The DOE said states would have to follow the definition or lose federal funding to schools.
But, according to a lawsuit filed by Weiser and eighteen other attorneys general, the new definition isn’t fully explained and is meant to be gleaned from parsing several executive orders designed to eliminate what the Trump Administration sees as “illegal” and “radical” DEI policies.
“Colorado, like many other states, refused to certify its compliance with these new requirements, explaining that there is no lawful or practical way to do so given the department’s vague, contradictory, and unsupported interpretation of Title VI,” Weiser’s announcement of the lawsuit said.
The lawsuit seeks to ban the DOE from withholding funding based on the new interpretation of Title VI. A final decision is still pending.
April 29: Protecting AmeriCorps From Federal Cuts
According to Weiser’s office, AmeriCorps has reduced its workforce by 90 percent due to Trump’s executive orders regarding workforce downsizing. The cuts have made it effectively impossible for the organization to operate, with any current AmeriCorps workers being told they will be terminated on June 24.
Filed on April 29, Weiser's AmericCorps lawsuit opposes the results of a February executive order by Trump directing federal agencies to reduce their workforces, which led to a 90 percent reduction in the AmeriCorps workforce. AmeriCorps is a service program where members undertake projects in exchange for a small stipend and scholarships for higher education.
In Colorado, AmeriCorps members work in wildfire mitigation, education and trail restoration among other tasks that span the entire state, according to an announcement from Governor Jared Polis supporting the lawsuit.
Weiser and his fellow attorneys general argue that because Congress appropriated the funding for AmeriCorps, Trump does not have the authority to shut down the program. Again, Weiser argues that Trump cannot take apart an organization that Congress established and funds.
On June 5, a Maryland judge ruled that Trump did not have the authority to take funding from AmeriCorps and reinstated grant funding to the organization. However, the judge ruled that Trump did have the authority to require workforce cuts.
"Every region in Colorado has directly benefited from the contributions of AmeriCorps members," Weiser said in a statement. "This win today is important, but I won’t stop fighting until we’ve permanently put a stop to the Trump administration’s reckless and shortsighted attempt to destroy AmeriCorps and the spirit of community service for which it stands.”
May 5: Preserving Wind Energy
On January 20, the Trump administration issued a memorandum on federal approvals for wind energy projects, effectively shuttering wind energy development. On May 5, Weiser and eighteen other attorneys general responded by suing the Trump administration. The attorneys argued their states should be allowed to pursue reliable energy generation projects and that Trump did not offer a reasoned explanation for the blockages. After the Trump administration attempted to dismiss the lawsuit, a judge in Massachusetts ruled the lawsuit can move forward.
May 5: Preventing the U.S. Department of Health and Human Services from Being Dismantled
As is the case for several other Weiser lawsuits, Kennedy Jr.'s actions are in question here. According to Weiser's office, over 10,000 HHS workers were terminated on April 1 alone as part of a restructuring that the lawsuit argues has caused chaos across the nation's healthcare system.
"Attorney General Weiser and the coalition argue that these sweeping actions are in clear violation of hundreds of federal statutes and regulations, and that the Trump administration does not have the authority to make these reckless changes," the AG's office wrote in an announcement of the lawsuit.
The coalition of attorneys general is asking the court to halt the mass firings and the restructuring while re-establishing critical health services that have been dismantled. On July 1, a Rhode Island judge issued a preliminary injunction preventing any further cuts or actions to implement the restructuring.
May 7: Maintaining Funding for Electric Vehicle Infrastructure
In 2022, Congress passed an act appropriating over $5 billion in funds to build infrastructure for electric vehicles across the country. According to Weiser's office, tens of millions of those dollars are meant to be used in Colorado, but Trump issued an executive order taking back the funding, including for projects that were already approved. Weiser's lawsuit seeks to restore the infrastructure funding.
In late June, a Washington judge issued a preliminary injunction for every state involved except Vermont, Minnesota and the District of Columbia after finding that all the other states — including Colorado — had proven harms from the executive order.
May 13: Refusing to Comply with Federal Immigration Crackdowns
On May 13, Weiser and nineteen other attorneys general filed two lawsuits over the same issue: the federal government attempting to force states to comply with federal immigration enforcement work to receive federal funding.
The first lawsuit is against FEMA the U.S. Department of Homeland Security and Secretary Kristi Noem. The second lawsuit is against the U.S. Department of Transportation and Secretary Sean Duffy. Both agencies, by direction of their secretaries, said they would stop issuing federal funds if local governments didn't conduct the immigration work desired by the Trump administration.
"In Colorado, we make the decisions on how our law enforcement resources are used here," Weiser said in a statement.
A Rhode Island judge issued a preliminary injunction on June 23 in the lawsuit against the U.S. DOT, writing that the department cannot withhold funding over a lack of immigration enforcement by states.
May 28: Protecting the National Science Foundation
In response to the National Science Foundation cutting funding for projects related to increasing the participation of women, minorities, and people with disabilities in STEM while also randomly capping the indirect costs of research projects at 15 percent, Weiser and other attorneys general filed a lawsuit. The lawsuit argues that Congress should be in charge of the NSF rather than Trump and seeks an order declaring the funding cuts and caps illegal.
The NSF lawsuit is on of a few from Weiser that has not been successful so far. On August 1, a New York judge declined a preliminary injunction to rescind the funding cuts. The judge ruled that the states hadn't done enough to show the action was out of bounds, and to let the lawsuit continue to play out without temporary relief.
June 9: Maintaining Machine Gun Conversion Ban
After the Trump administration made plans to redistribute devices called forced reset triggers that make semiautomatic weapons work like machine guns, Weiser and other attorneys general sued the Bureau of Alcohol, Tobacco, Firearms, and Explosives. Before May 16, the ATF had classified those devices as machine guns, which made FRTs against federal law. However, the White House then directed the ATF to stop enforcing that law and give back previously seized FRTs. As a result, the lawsuit asks the ATF to stop redistributing the devices as doing so is a violation of federal law, and could contribute to violations of state laws banning FRTs.
Weiser filed a lawsuit on April 29 after the federal government cut 90 percent of AmeriCorps, which works to mitigate wildfires in Colorado.
Catie Cheshire
Colorado, following California's suit, has stronger standards for vehicle emissions than the federal government requires. Under Trump's direction, the EPA has moved to rescind waivers granted to California that allow those more stringent standards. This lawsuit seeks to keep the waivers in place and continue to allow states to regulate vehicle emissions as they see fit.
June 24: Fighting Federal Funding Cuts by DOGE
According to Weiser's office, many of the cuts to federal programs made by DOGE have been justified by a federal rule saying agencies may terminate an award of federal funding if it “no longer effectuates … agency priorities.”
The subject of this June 24 lawsuit is questioning that justification.
"The Trump administration’s decision to invoke a highly questionable regulation for terminating funds based on their changed ‘agency priorities’ is unlawful," Weiser said in a statement. "We are challenging this action because Colorado and other states accept hundreds of billions of dollars a year to combat violent crime, educate students, protect clean drinking water, conduct lifesaving medical and scientific research, and safeguard public health. All these priorities are at risk of funding cuts based on the misuse of this regulation."
The lawsuit wants a court to declare that a new presidential administration does not constitute a change in agency priorities. Specifically, the lawsuit asks the court to rule that grants awarded prior to Trump's election should not be able to be rescinded.
July 1: Blocking ICE from Receiving Medicaid Data
In response to the HHS giving ICE and the Department of Homeland Security unrestricted access to personal medical information through Medicaid, Weiser joined other attorneys general to sue.
The lawsuit argues that transferring such data is illegal, asking for a judge to prevent any new data transfers for immigration enforcement purposes.
In a statement, Weiser argues that the decision has created "fear and confusion that will lead non-citizens and their family members to disenroll, or refuse to enroll, in emergency Medicaid for which they are otherwise eligible, leaving states and their safety net hospitals to foot the bill for federally mandated emergency healthcare services."
July 1: Regaining Youth Mental Health Funding
Weiser joined a second lawsuit on July 1, this one suing the DOE for withholding $1 billion in grant funding that had previously been allocated to combat the youth mental health crisis. According to Weiser's office, around $10 million was appropriated to Colorado between both colleges and high schools. The funding went toward recruitment and retention of mental healthcare professionals in schools throughout the state.
The attorneys general believe there is no legal justification to withhold the funds and ask for a judge to release the money.
July 14: Preventing Education Funding Cuts
This Weiser lawsuit seeks to preserve $80 million in federal dollars for education in Colorado. In total, the Trump administration is considering withholding $6.8 billion in education funding nationwide. Affected programs include those that help migratory children and English learners, improve classroom instruction, upgrade technology in classrooms and support community education centers and adult learners.
"Without this funding, districts across Colorado will be forced to cut critical services just weeks before the school year begins," Susana Cordova, Colorado education commissioner, said in an announcement. "The United States has long believed that every child, regardless of background or ZIP code, should have the resources they need to thrive. We must continue to support the American dream, which starts with vibrant schools and support for kids.”
The lawsuit argues that withholding the funds ignores federal regulations, and asks a court to prevent the funds from being withheld.
July 16: Maintaining Important FEMA Program
The Building Resilient Infrastructure and Communities program housed within FEMA allocates money for states to invest in infrastructure projects that help fortify communities against natural disasters. Earlier this year, the Trump Administration canceled the program entirely. Along with nineteen other attorneys general, Weiser sued to reinstate the program, arguing that the president cannot unilaterally cancel the BIRC because Congress established it.
July 17: Preserving Healthcare for 1.8 million people
Through the HHS Centers for Medicare & Medicaid services, the Trump administration created a new rule that could kick up to 1.8 million people off health insurance and raise premiums significantly for many who remain covered. Over 300,000 people in Colorado are covered through Medicare and Medicaid, according to Connect for Health Colorado, the state's insurance exchange. The new rule would kick in August 25 if a judge does not intervene beforehand, which is what the attorneys general requested.
July 21: Protecting Safety Net Programs
In July, the Trump Administration prohibited state safety net programs like Head Start and community health centers from serving people who cannot verify their immigration status. In the past, states have been allowed to serve anyone, regardless of immigration status, with those programs. Weiser argues that many such programs don't even have the capacity or resources to verify immigration status. As a result, many programs will end completely while others will be severely limited by the ruling. Because of this, several state attorneys general sued, calling the prohibition unlawful and asking for immediate relief as the case moves through the court system.
July 28: Safeguarding SNAP data
After the United States Department of Agriculture requested the Supplemental Nutrition Assistance Program turn over personal information of participants or risk having funds withheld in May, attorneys general responded with a July 28 lawsuit. Colorado is supposed to receive $96 million from SNAP this year, according to Weiser's office.
The lawsuit argues that the order violates privacy laws, requesting that the courts determine the action is unlawful and prohibit such restrictions on SNAP funding.
July 29: Keeping Planned Parenthood Eligible for Medicaid Funding
Weiser, along with 21 other state attorneys general and the District of Columbia, sued over a Trump administration provision passed in the controversial "Big Beautiful Bill" that blocks Medicaid funding for Planned Parenthood locations nationwide for services like cancer screenings, birth control and sexually transmitted infection testing.
"Congress specifically included the Defund Provision in the massive spending bill to target and punish Planned Parenthood for providing abortion access and advocating for reproductive health options for patients," Weiser says in a statement.
The lawsuit says the provision defunding Planned Parenthood breaches federal law and would cause undue harms to states.
