Meet 'Iron Stache,' the Democrat running to replace Paul Ryan in Wisconsin

But with Ryan announcing on Wednesday that he will not seek re-election, Bryce is now the most high-profile Democratic candidate in an open race in Wisconsin's 1st Congressional District -- a district national Democrats have targeted as a potential pickup in the midterms.

"The mission was to repeal and replace Paul Ryan with a working person. Obviously, we've been able to push him out ... but there's still a lot of work to do," Bryce, a Latino, a veteran and cancer survivor, said in a phone interview with CNN. "We're going to face the same kind of money machine that's going to come in place and try to prop up whoever is the Republican nominee."

Bryce has raised $4.75 million since launching his campaign in June 2017, according to the campaign. The Democratic Congressional Campaign Committee included Bryce and the district on its "Red to Blue" campaign program -- a list of seats Democrats believe they have the best chance of flipping in 2018.

After Ryan's retirement announcement, CNN moved the seat in its race ratings from Likely Republican to Lean Republican.

His campaign announcement video, which drew national attention, went after Ryan for repealing Obamacare and prominently featured Bryce's mother, who has multiple sclerosis.

At the end of the video, Bryce offered to trade places with Ryan. "Paul Ryan, you can come work the iron, and I'll go to DC."

Bryce supports a $15 hourly minimum wage, increased staffing at the Occupational Safety and Health Administration, which oversees job site safety, Medicare for all, and Paid Family Medical Leave.

Bryce has made access to affordable healthcare a key issue in his campaign. His mother lives with multiple sclerosis, and his father, a retired cop, is in an assisted-living facility. He himself is a testicular cancer survivor. When was diagnosed in his late 20s, he was working two full-time jobs but had no health insurance. So, he says, he got healthcare from a nearby medical school teaching hospital.

"Everybody should be able to see a doctor," Bryce said. "It's not that we can't afford to, it's just that we chose not to make it a priority."

Bryce has spent the last several years working as a political coordinator for Ironworkers Local 8 and as a member of the Milwaukee Area Labor Council board of directors. He served on the Racine Labor Council and helped found the Wisconsin Chamber of Commerce for Veterans.

He ran and lost in the primary for a state assembly seat in 2012, lost a primary race for the Racine County Board of Education in 2013 and lost the general election for a state senate seat in 2014. But Bryce continued to work full time during each of those races and did not have dedicated campaign staff, which he does now.

When Bryce decided he wanted to run, he caught the eye of political consultant Bill Hyers, notable for managing Kirsten Gillibrand's first run for Congress in 2006 and New York City Mayor Bill de Blasio's 2013 campaign. Hyers is now chief strategist for Bryce's campaign.

"It was refreshing to see someone running against the speaker with complete confidence," Hyers said. "I think it's the desire to fight. His military background, his labor background -- he didn't mind taking on the tough fight even if it was against the man."

Hyers, who helped make Bryce's campaign video, said, "His authenticity comes across and he's not trying to be anything but what he is," Hyers said.

With Ryan out of the race, the most prominent Republican candidate is Paul Nehlen, who has recently attracted attention for his anti-Semitic tweets. Nehlen lost to Ryan in the 2016 Republican primary by nearly 70 points.

Other potential candidates have until June 1 to file their declarations of candidacy for the seat.

The primary is August 14.