Populist Democrats are gearing up for another test Tuesday night, when ironworker and labor activist Randy Bryce attempts to win a primary in Wisconsin’s 1st District.

Bryce is running in a suburban Milwaukee seat that President Donald Trump carried by a 10-point margin in 2016. Initially he was running to oust House Speaker Paul Ryan. But his insurgent campaign changed when Ryan announced in April he wasn’t seeking re-election, leaving the seat vacant.

Despite Ryan’s retirement, Bryce’s bid continues. He is betting that come November his working-class roots and progressive politics — backing Medicare for All, a $15 minimum wage and abolishing U.S. Immigration and Customs Enforcement — can help him flip a seat that Republicans have held for more than two decades.

But first, he must win a primary against Cathy Myers, a teacher and member of the Janesville school board in Ryan’s hometown.

Myers has raised a staggering amount for her bid since entering the race in June 2017, pulling in more than $1.2 million, according to financial records filed with the Federal Election Commission. But Bryce dwarfs her in the fundraising race, having raked in more than $6.2 million — thanks in part to viral campaign videos and celebrity endorsements.

Bryce has become something of a national figure in the past year, winning the endorsement of dozens of elected officials, progressive groups, unions and even the Democratic Congressional Campaign Committee, which added Bryce to their “Red to Blue” list of candidates they think can flip districts across the country.

Yet a poll from a Republican super PAC (so take it with a grain of salt) from early July showed the race between Myers and Bryce as a dead heat. As his profile has risen, Bryce has been plagued by news reports of a past arrest record for driving under the influence, as well as reports he was delinquent on child support payments.

In a debate in July, Myers painted herself as the more electable candidate.

“We need to elect someone who can not only win, but serve,” Myers said at the debate, according to the Milwaukee Journal Sentinel.

The winner of the primary will face a Republican in a district that the nonpartisan political handicapping website Inside Elections rates as “Lean Republican.”

Republicans also have a crowded primary field in the contest that includes Paul Nehlen, a white supremacist who lost a GOP primary to Ryan in 2016. Ryan endorsed University of Wisconsin Regent Bryan Steil in the Republican primary.