But could this be the last biannual money and TV ad-athon in the 6th? If Coffman is able to pull off a fourth consecutive victory in this suburban swing district that includes much of Adams, Arapahoe and Douglas counties, it would cement him as an entrenched congressman, and perhaps take him out of Democratic targets in future election cycles.
If he does it again, you just might have to call him Iron Mike.
"Coffman has been semi-officially endangered since his seat was redistricted in 2011. Since then, he's survived three challenges," says University of Denver political science professor Seth Masket. "[This year] is shaping up to be possibly the strongest Democratic tide since 2006. If Coffman can survive this, he can probably survive whatever the Democrats throw at him."
Not so fast, though, say Democrats. There's plenty of reason to believe that 2018 in particular could be different, and operatives on both sides of the aisle acknowledge that this year presents a completely different challenge for the fifth-term Aurora native.
An unpopular Republican president is tweeting on Pennsylvania Avenue in a national political environment that's expected to heavily favor Democrats. A record number of congressional Republicans have announced their retirements as they brace for a potential Democratic wave.
Though they're a few months old at this point, early polls have pointed to a tight race in the 6th, and Democrats are fielding a different type of candidate: Former Army Ranger Jason Crow, who's never held office, is the leading contender to win his party's primary and battle Coffman, who has never run with a Republican in the White House.
"This is the toughest environment Coffman has run in, in a district that is trending away from him," says Rachel Irwin, regional spokeswoman for the Democratic Congressional Campaign Committee, which has labeled the 6th District as one of its 24 "red to blue" target flip seats. "You have the perfect storm of an electorate that is well educated and diverse. We fully expect to flip this seat this cycle."
voting record in Congress that they argue falls in line with Trump's priorities.
"I think that’s the message on Coffman: He’s not Trump, but he enables Trump by voting for Trump's agenda 95 percent of the time in Washington," says Eric Walker, the Colorado Democratic Party's communication director.
But perhaps more successfully than fellow GOP member Senator Cory Gardner, Coffman has been able to separate himself from the mainstream Republican brand, one that would doom more conventional candidates in a Democratic-tilting district such as the 6th.
"Despite Mike increasing his raw vote margin of victory every cycle since 2012, Dem Super PACs (specifically two Pelosi-affiliated groups — the DCCC and House Majority PAC) have only increased their spending in negative attack ads on the airwaves and in the mailboxes," writes Coffman spokesman Tyler Sandberg in an email. "We’re ready for the fight."
Why does this congressional race matter so much? Colorado's other six congressional districts are about as competitive as a beer-in-hand kickball game. The 6th District, which voted for Hillary Clinton by a convincing nine-point margin but turned around and elected Coffman by around eight, is Colorado's only truly competitive House race each cycle. Another win by Coffman could cement this race as a likely Republican hold in future elections — or at least until redistricting after the 2020 Census.
"If Nancy Pelosi and her liberal donors want to continue wasting their money trying to take out Coffman, so be it," Sandberg writes. "Voters in the sixth district know that Mike fights for them, not (Democratic House minority leader) Nancy Pelosi, and they have long appreciated his willingness to stand up to both sides."
After squeezing out a two-point victory in his first election after 2011 re-districting moved him from a safe Republican seat to a much more competitive one, Coffman jumped his margin of victory to nearly ten points in each of his last two campaigns. Coffman defeated Democrat Andrew Romanoff by 8.9 points in 2014, and he followed that up by defeating Democrat Morgan Carroll by 8.3 points in what was generally expected to be a closer race. Coffman's popularity in immigrant communities in particular is believed to be a major part of his bipartisan appeal, and some of Coffman's harshest rhetoric against Donald Trump is often saved for immigration issues.
Probable re-districting after the 2020 Census, including the high possibility of Colorado receiving another congressional district, will make this all moot in three years, by which point Coffman will be 65 and potentially approaching retirement.