"Another progressive candidate entered the race [Tillemann], and we would split the progressive vote, and the establishment candidate would go on to win again," McArthur says. "Mike Coffman would win again."
Tillemann, a 35-year-old entrepreneur and the grandson of Colorado's first female lieutenant governor, jumped into an already crowded field last month that also includes an early favorite, veteran Jason Crow, and Aurora attorney David Aarestad.
McArthur, meanwhile, has decided to take his self-described progressive views into the race for Colorado Secretary of State, where he'll be looking to unseat incumbent Republican Wayne Williams. McArthur says he takes issue with Williams's recent decision to partially comply with a Presidential Advisory Committee seeking voter registration information.
"It's a slippery slope that I'm uncomfortable with," McArthur says. Approximately 3,700 Colorado voters that have voluntarily taken their names off voting rolls in recent weeks in response to the federal government action. "I wonder what precedent this sets if more information is requested."
That said, McArthur, as Williams has also done, advises registered voters upset with the federal government's information requests to stay on voter rolls.
"I don't think it's a good idea to de-register," McArthur says. "I don't know where [the thought of de-registering being a good idea] came from. The Democratic party is trying to discourage people from doing that."
If elected, McArthur wants to explore automatically registering eligible voters as soon as they turn eighteen. He also advocates for looking into new technologies geared toward advancing Colorado's typically high voter-turnout rates (Colorado ranked fourth in the presidential turnout vote among eligible voters last November).
"Colorado has a high voter turnout, so we're already doing pretty well," McArthur says. "But any extra mile we can go, we should go that way."
As of Friday, July 29, McArthur had not filed the paperwork needed to run for secretary of state; he says he's "in the process" of completing it. Attorney Jena Griswold and businessman Phillip Villard have filed to run as Democrats against Williams.