In this Feb. 1, 2020, file photo, U.S. Sen. Bernie Sanders, I-Vermont, speaks at a campaign rally in Cedar Rapids, Iowa. Credit: John Locher / AP

WASHINGTON — Bernie Sanders has long argued, but not proved, that his big government populism can win over voters in the largely white, rural communities that flocked to Republican Donald Trump in recent elections.

Now as the chief Senate shepherd of a $3.5 trillion budget proposal, Sanders believes he has another chance to test the theory.

The Vermont senator is embarking on a two-stop swing through Trump country this weekend, promoting a budget plan packed with progressive initiatives and financed by higher taxes on top earners. He’s specifically targeting two congressional districts where Trump’s vote totals increased between 2016 and 2020.

“What we are doing is precisely what working-class families, Republican, Democrat, independent, want,” Sanders, who helped negotiate the proposal as chair of the Senate Budget Committee, said in an interview. “And we’re going to pay for it by demanding that the wealthiest people, and largest corporations that are doing phenomenally well, start paying their fair share of taxes.”

Sanders will hold town halls in West Lafayette, Indiana, on Friday night and Cedar Rapids, Iowa, on Sunday. He said he’ll highlight the difference between the two parties since congressional Republicans in years past approved tax cuts for wealthy Americans but are expected to universally oppose a plan Sanders calls “the most consequential piece of legislation” since Frank Delano Roosevelt’s New Deal in the 1930s.

It could be a tough sell for the face of the progressive movement. Republicans have already begun using Sanders — along with fellow democratic socialist and New York Rep Alexandria Ocasio Cortez — in ads warning voters that the country is edging toward socialism.

Sanders saw his political star first rise to national prominence by nearly winning the 2016 Democratic Iowa caucus, and he won that year’s Indiana Democratic primary over Hillary Clinton. As he pushed his party to the left and drew in voters frustrated by mainstream Democrats, Sanders and his supporters advocated for reaching beyond the traditional base by making appeals to the white, working class that can attract Republicans or nonvoters.

“He has a lot of credibility with a lot of audiences that aren’t just progressive,” said Maurice Mitchell, national director of the progressive advocacy group the Working Families Party. “He an outsider. He’s a populist. And, in fact, the thing that we’ve always said works best against rightwing populism is progressive populism.”

But evidence that Sanders has particular sway with Trump voters is limited. According to data from the Pew Research Center, only about 3 percent percent of people who consistently supported Sanders during 2016 the primary season, and were confirmed to have voted in the general election, said they ultimately supported Trump, compared with 81 percent who reported voting for Democratic nominee Hillary Clinton.

An Associated Press-NORC Center for Public Affairs Research poll in February 2020 found that 17 percent of Republicans had a favorable view of Sanders, roughly the same share of Republicans who had a favorable view of Biden.

Sanders next chance to make his case is a budget proposal that promises universal prekindergarten and tuition-free community college, while increasing federal funding for child care, paid family leave and combating climate change. It also expands health care coverage through Medicare, creates pathways to citizenship for millions of immigrants in the country illegally and encourages states to adopt labor-friendly laws.

Republicans say the plan is loaded with unnecessary spending and tax increases. But Democrats, as long as they stay united, can use their narrow advantage in each congressional chamber to muscle it through anyway.

Sanders said his trip could increase pressure on Republicans who oppose measures that are broadly popular with working-class Americans, regardless of ideology.

“This is the people’s budget. This is the budget that will impact tens of millions of lives in this country: the elderly, the children, the working families, the middle class,” Sanders said. “So it is appropriate to me that the chairman of the budget committee get out and around the country, hear what people have to say. Explain what we’re trying to do.”

Although Sanders is heading to red states, his trip isn’t exactly into hostile territory. His 2016 and 2020 presidential bids were popular with college students and West Lafayette is home to Purdue University. He similarly remains popular in Iowa, which means his Cedar Rapids event may attract far more longstanding Sanders supporters than potentially persuadable Republicans.

Still Sanders scoffed at suggestions that his presidential campaigns were more successful at energizing liberals, many of them wealthy, than at growing his party’s appeal with crossover voters.

“Poll after poll shows that the American people want the wealthiest people, large corporations, to pay their fair share. This is not wealthy liberals, this is working class Americans,” Sanders said, adding of his ability to sell the budget proposal to independents and Republicans, “I think it’s part of my job and I think I’ll do OK.”

There is some bipartisan support for key parts of the budget proposal. A July AP-NORC poll found that 62 percent of Republicans backed funding for caregivers for the elderly. At least 4 in 10 Republicans said they supported funding for free preschool, affordable housing, broadband internet and local transit, and close to 3 in 10 said they supported funding for free community college.

Sanders’ trip follows President Joe Biden and his allies traveling the country to promote the administration’s efforts to strengthen the post-coronavirus pandemic economy. Sanders said he’s confident in Biden’s support for the proposal.

There are no plans for the two former rivals to travel together to promote the proposed budget, though he wouldn’t be opposed to doing so, Sanders said.

The administration’s economic agenda has been overshadowed in recent days by violence and chaos in Afghanistan. But Sanders said Americans from across the political spectrum understand that what’s occurring there and with their pocketbooks back home “are separate issues.”

Still, the budget process has not gone entirely smoothly even within Sanders’ own party. A group of moderate House Democrats threatened to derail the budget blueprint, and only dropped their opposition after House Speaker Nancy Pelosi promised that a vote on a separate, $1 trillion public works package which has already passed the Senate would come late next month.

Mitchell called such moderate Democrats “obstructionists.”

“That small but loud crew, they don’t have a popular base,” Mitchell said. “People want to get this passed.”

Sanders, however, will be in the territory of moderate Iowa Democratic Rep. Cindy Axne, whose staff said she doesn’t plan to attend his Sunday event. Republicans believe Sanders hitting the road could ultimately hurt his party during next year’s midterms, when control of Congress is at stake.

“Democrats’ embrace of socialism helped us pick up seats in 2020, and will continue to help us in the midterms,” National Republican Congressional Committee spokesperson Mike Berg said.

Sanders countered that he’s not worried about his visit making things politically uncomfortable for Axne, saying, “This is the right thing to do for America, I think in her district, or in any other district in this country.”

“If I had the time, I’d love to go to 50 states in this country,” Sanders said. “So we’ll pick and choose and get out there when we can.”

Story by Will Weissert. Associated Press Director of Public Opinion Research Emily Swanson contributed to this report.