Rep. Dan Lipinski is a rare Democrat who opposes abortion rights. He’s also a rare incumbent who is in a real race in the Illinois primary election on Tuesday night.

Lipinski, an incumbent Congress member in the Third Congressional District, faces Marie Newman, a first-time candidate and a supporter of abortion rights who has been endorsed by pro-choice groups like NARAL Pro-Choice America and Emily’s List, which works to get pro-choice Democratic women elected to office. The race is tight — a poll conducted on behalf of NARAL at the end of February put Lipinski just 2 points ahead of Newman. Recently, the Democratic Congressional Campaign Committee and House Minority Leader Nancy Pelosi (D-CA) stepped in to back Lipinski.

The primary will provide an early test of a deep conflict emerging in the Democratic Party: In the Trump era, Democrats see an opening to take back the House. But to do it they’ll need to flip swing voters or boost turnout — or both.

Democrats like Lipinski believe the party needs to move to the right on issues like abortion, immigration, and health care to appeal to these swing voters. The progressive wing wants to keep those liberal priorities but repackage them as part of a broader populist message — one that Sen. Bernie Sanders (I-VT) proved could appeal to Democrats in his 2016 primary bid. The Third Congressional District swung for Sanders by 8 points.

“We need to have a big-tent party,” Lipinski told an Illinois radio station earlier this month. “We need to rally around those issues that can bring all Democrats together.”

Newman doesn’t think that means abandoning long-held Democratic beliefs around reproductive health care and other rights.

“I believe in giving a fair deal to workers and working families,” she told Vox. “I also believe that everybody’s rights are important.”

The result of Tuesday’s primary won’t settle this debate — but it will certainly offer one data point for the party as it grapples with what the future of the Democratic Party will look like in the age of Trump.

Lipinski is a longtime incumbent with a right-leaning history

Lipinski has represented Illinois’s third district, which includes parts of Chicago and its suburbs, since 2005. Before that, his father, William Lipinski, held the seat — the two have represented the district for a combined 35 years, according to the New York Times.

Lipinski, who has not responded to Vox’s requests for comment, is a co-chair of the Blue Dogs, a coalition of right-leaning House Democrats. He has voted against the Affordable Care Act, the DREAM Act, and legislation prohibiting job discrimination on the basis of sexual orientation. He has spoken at the March for Life and voted to defund Planned Parenthood and received high ratings from the National Right to Life Committee.

In interviews, Lipinski has said the Democratic Party is endangering its future by moving too far to the left. “This is part of the reason Donald Trump won,” he told the New York Times earlier this month. “Democrats have chased people out of the party.”

“There are those who want to have a ‘Tea Party of the left’ in the Democratic Party,” he said in an interview with Illinois radio station WGN-AM 720.

“We have to be for working men and women, for being champions of the middle class and taking care of the bread-and-butter issues that people really care about and restoring the American Dream.”

For him, those issues include supporting manufacturing through “Buy American” policies and opposition to trade deals like the Trans-Pacific Partnership. He says he now supports the Affordable Care Act and is a co-sponsor of the bipartisan BRIDGE Act, which would provide temporary protection from deportation for DACA recipients.

The Democratic Congressional Campaign Committee (DCCC) has backed Lipinski after what many — including the candidate — saw as a delay. A DCCC aide told Vox there was no delay and that “the DCCC is supportive of all incumbents.”

To Newman and her supporters, however, Lipinski is “a Democrat in name only,” as her campaign manager put it in a statement.

“He likes to say he’s a centrist, he’s not. He is a Republican,” Newman told Vox. “There is not a division in the Democratic Party — he just is a dinosaur.”

Newman is a first-time candidate challenging Lipinski from the left

Newman is no stranger to public life. About 10 years ago, after finding out her oldest child was being severely bullied, she worked with around 100 other families to institute an anti-bullying program in her town.

That led to work on a state anti-bullying task force, the directorship of a national nonprofit called Team Up to Stop Bullying, and a seat at President Barack Obama’s White House summit on the issue. Newman, whose daughter came out as trans three years ago, has also done advocacy work on LGBTQ rights, as well as serving as the Illinois spokesperson for the gun-control group Moms Demand Action.

She had considered running for office in the past — “our rights were being taken away insidiously over the last few years,” she said, citing Republican attacks on health care access and Planned Parenthood. But, she added, “what I think pushed me over the edge probably was the Trump election.”

“The next day I, like most of America, sat in my pajamas and cried all day,” she said. Then she decided to take matters into her own hands. “The phrase I use most frequently is, ‘Nobody coming to save us.’ We have to save us.”

Now she’s running on a decidedly left-wing platform that combines support for health care for all and a $15 minimum wage with support for reproductive health care and civil rights for immigrants and LGBTQ people.

“The Democratic Party is about working families and the middle class,” she said. “That’s who we are, and we have to get back to that.” But for her, unlike for Lipinski, there’s no conflict between supporting working families and advocating for issues like LGBTQ equality and reproductive rights. When I asked her if she, like some on the left, saw a distinction between pocketbook issues and so-called “identity politics,” she was blunt.

“I don’t believe in identity politics,” she said. “I believe in everybody’s rights.”

Why Lipinski is vulnerable now

Groups like NARAL have reportedly been looking to unseat Lipinski for a while, but he might be especially vulnerable this year for a couple of reasons.

The first one is Arthur Jones, who is running unopposed for the Republican nomination.

A Holocaust denier and former member of the American Nazi Party, Jones told the New York Times in February that he doesn’t believe in racial equality. The chair of his state’s Republican Party has said that “the Illinois Republican Party and our country have no place for Nazis like Arthur Jones.”

“The Republican likely nominee is insane,” said Jennifer Lawless, director of the Women & Politics Institute at American University. “As a Holocaust denier, it’s unlikely that he’ll win, which means that there’s virtually no risk involved in supporting the challenger to an incumbent.” Democratic voters don’t have to go with the safe, known quantity if they think Jones is sure to lose no matter what.

The other reason is Lipinski’s record. He may be a Blue Dog, but his district is just blue — it’s gone Democratic in the past four presidential elections. More than two-thirds of the district identifies as pro-choice, said Celinda Lake, a Democratic pollster and political strategist. “He’s simply out of touch with his voters,” she said.

That could matter now more than ever. “If we look at the Women’s March and the activism that we’ve seen among Democratic women in particular,” Lawless said, “we’ve seen quite a bit of attention given to issues of social justice and reproductive rights.”

A 2017 poll Lawless and a colleague conducted with Politico found that for Democrats and especially for Democratic women, “issues having to do with affordable health care, reproductive rights, civil rights and civil liberties were far more salient to them than they had been in the past, and they were far more active around these issues than they had been in the past,” she said.

Those are the issues where Lipinski is likely to be out of step with Democratic women. “Across the board on social issues, he’s not very progressive,” Lawless said.

What the race says about the rest of the country

Ever since Trump’s election, there’s been a debate about whether Democrats need to move right on social issues to appeal to more voters. Lipinski isn’t the only one to endorse that view — Sanders has argued that Democrats may need to embrace anti-abortion candidates to be a “50-state party.” (Recently, however, Sanders endorsed Newman.)

A win for Newman could be a rebuke to that viewpoint, which some argue misrepresents the American electorate. “It’s thinking that’s out of date,” said Lake. “A solid majority of Americans are pro-choice.”

“We’ve seen proudly pro-choice candidates win up and down-ballot in Virginia and even in Alabama,” said Ilyse Hogue, president of NARAL. “There is a new conversation happening, and it is one about respecting people’s personal paths.”

Beating an anti-abortion candidate might not be as difficult in the Chicago suburbs as it would be in the South. Still, Lipinski has served seven terms in Congress. A Newman victory might be a sign that the engagement around social issues found in the Politico poll has real power at the ballot box.

“There is no question that the election of 2016 was a national reckoning for people,” Hogue said. “When you look to your elected leadership and you see that they’re standing on the side of Trump and that bankrupt set of values, it really feels like you’re not safe anywhere.”

“I think Marie is part of this wave that we’ve seen that’s saying, ‘Oh no, we are taking this country back and we are moving it into the future,’” she added.

Newman’s campaign also represents a larger strategy by some Democrats — Joe Kennedy is another — to present economic and social issues as fundamentally linked.

The idea “that economic security is embedded in notions of social justice” could help Democrats win a broad swathe of voters, Lawless said. “I think that if they’re able to deliver that message successfully, that’s how the Democrats can appeal not only to the people who have always voted for them or who are progressive but also to some of those disaffected people in the Rust Belt who felt like their own economic security and their economic growth was not as important to Democrats as these hifalutin liberal ideals.”

If Newman wins her primary with this strategy, it could be a good sign for its success in November. For now, she’s careful to cast her battle with Lipinski not as a single-issue contest, but as one with broad implications.

“Some media want this to be a fight around abortion,” she said. “This is about everybody’s rights and supporting people’s quality of life, period.”

Correction: An earlier version of this article mistakenly stated that the Democratic Congressional Campaign Committee had endorsed Rep. Dan Lipinski. The DCCC does not issue formal endorsements.