In the opening minutes of a debate during Sherrod Brown’s successful 2006 campaign for Senate, the Republican incumbent attacked him over “partial-birth abortion,” a phrase often weaponized by conservatives at the time to paint Democrats as somewhere between immoral and murderous.
Mr. Brown, a Democrat from northeast Ohio in the House at the time, glanced at his notes. He opposed “late-term abortion,” he said in a measured voice. He denounced the mere idea that Congress would limit any procedure that could “save a woman’s health.”
With that, he quickly pivoted. Mr. Brown used the rest of his time to burnish his political brand as a blue-collar economic populist.
Nearly 18 years later, abortion will again be a central point of contention as Senator Brown fights for re-election against one of three Republicans trying to unseat him next year. One difference, other than that his shaggy dark hair is now shaded with gray, is that he is preparing to fully lean into his defense of abortion rights.
“This issue’s not going away,” Mr. Brown said in an interview. “Women don’t trust Republicans on abortion, and they won’t for the foreseeable future — and they’re not going to trust these guys running against me.”
Since the Supreme Court overturned Roe v. Wade last year, abortion rights has become an invaluable political asset for Democrats. They have leveraged the issue to hold onto control of the Senate, limit losses in the House and, this month, fuel victories in key state races across the Midwest and the South.
But perhaps the toughest test for the issue’s power will come in Senate contests like Mr. Brown’s in Ohio and Senator Jon Tester’s in Montana. The fate of the razor-thin Democratic majority in the chamber could well be sealed in those two places, by the same voters who have installed Republicans in every other statewide office.
So far, voters even in conservative states have consistently prioritized abortion protections over their partisanship. That was true last year in Kansas, where 59 percent of voters rejected a measure to remove abortion rights protections from the State Constitution, and again this month in Ohio, where 57 percent of voters agreed to enshrine such rights in their Constitution.
The open question is whether Mr. Brown, 71, and Mr. Tester, 67, can maintain their invaluable political personas while — for the first time in their lengthy careers in public office — persuading their constituents to keep abortion rights front and center when voting next year.
Both Democrats have long supported abortion rights, but their electoral successes trace back to carefully tailored campaigns that catered to local issues over dominant national ones like abortion. That individuality was how both men won re-election in 2018, even though their states voted for Donald J. Trump in 2016 and 2020.
For Mr. Tester, this has meant campaigning on policies he has focused on in the Senate, where he serves on committees overseeing agricultural, Native American and veterans issues.
His first television ads this campaign strike similar tones. One features Mr. Tester — a paunchy former schoolteacher with a flattop haircut and a left hand missing three fingers from a boyhood accident with a meat grinder — describing himself as both physically and philosophically different from his congressional colleagues.
“I may not look like the other senators,” Mr. Tester says, “but that’s not stopping me from making Washington understand what makes Montana so special.”
In Ohio, Mr. Brown has built his reputation on middle-class economic issues, including fighting corporate tax breaks and the high cost of health care. In a 2004 book, “Myths of Free Trade: Why America Trade Policy Has Failed,” he argued that unregulated trade deals had reopened the country’s class divide.
This year, Mr. Brown’s campaign has already released a video attacking his three potential Republican challengers as extreme on abortion. In Montana, the Democratic Party has taken a similar approach on behalf of Mr. Tester.
“The thing I think a lot of people miss with Sherrod is that he knows abortion is an economic issue,” said Nan Whaley, a Democratic former mayor of Dayton, Ohio, who ran for governor last year. “Abortion rights and abortion access maybe wasn’t discussed as much in previous campaigns, but that’s because it was before the fall of Roe.”
The task for the two Democrats will be complicated by a political headwind that neither senator has confronted: seeking re-election on a ballot topped by an unpopular president from their own party.
Both first won election to the Senate by unseating incumbents in 2006, when discontent over the Iraq war and Republican corruption scandals helped Democrats make gains in Congress.
Each was re-elected in 2012, when Democrats scored huge majorities from Black and Hispanic voters as President Barack Obama won a second term. They won again in 2018, a Democratic wave year propelled by opposition to Mr. Trump.
Republicans are already trying to massage their message on abortion. The National Republican Senatorial Committee is coaching candidates to oppose a national abortion ban and to clearly state their support for exceptions when it comes to rape, incest or a woman’s health.
But not all Republicans are on board, as the party’s Senate primary race in Ohio shows. One top candidate, Frank LaRose, the Ohio secretary of state, has supported a national ban and opposed exceptions for rape and incest — and also unsuccessfully campaigned against the abortion ballot question.
Another contender, Bernie Moreno, a businessman seeking his first elected office, has said he supports exceptions for rape, incest and the life of the woman, but he told a reporter from Breitbart News last year that he did not. He has also expressed support for a 15-week federal ban.
The third leading candidate, Matt Dolan, a state senator, opposed the state’s constitutional amendment this month, but he has a more moderate record on the issue than his opponents. Mr. Dolan opposes a national ban and has criticized abortion ban proposals in Ohio that haven’t included the three main exceptions.
“Most Americans agree there should be reasonable limits on abortion and abortion policy will primarily be made at the state level,” Mr. Dolan said in a statement, adding that Mr. Brown held “extreme” views on the issue.
Some Republicans have said that Ohio’s ballot referendum means the abortion issue will have less urgency in the state next year. But Democrats contend that Republican support for a federal ban would help keep the issue alive, arguing that such a measure would undermine the will of Ohio voters.
A poll commissioned by the Democratic Senatorial Campaign Committee recommended that messaging focus on G.O.P. support for a “national abortion ban” and that politicians should not be involved in “personal medical decisions.” Abortion rights groups have encouraged candidates to simultaneously adopt a “proactive” platform that calls for expanding access to contraception and maternal health resources while highlighting Republican involvement in abortion restrictions.
“Campaigns need to quickly define who the villains are here: Republicans overturned Roe, Republicans have been campaigning against Roe for decades, Republicans have been pledging to create a court that would overturn Roe,” said Mini Timmaraju, the president of Reproductive Freedom for All, one of the country’s largest abortion rights groups. “They got it, they did it, they’re responsible. Pin it on them. Do not flinch.”
Neither Mr. Brown nor Mr. Tester has been shy about supporting abortion rights.
Mr. Tester campaigned in 2018 with Cecile Richards, who had recently stepped down as the president of Planned Parenthood. He said recently that abortion rights had clear resonance in Montana, where libertarian-leaning voters tend to reject perceived government intrusion.
Still, Mr. Tester has mostly tailored his campaigns around issues closer to the Continental Divide in his state than the partisan divide in Washington.
Mr. Brown won his first political office in 1974, the year after Roe v. Wade was decided. He has proudly highlighted his 100 percent voting score from Planned Parenthood Action Fund and Reproductive Freedom for All.
“My focus has always been on civil rights and women’s rights,” he said. “That leads to a better economy, too — when women have better access to child care and can make decisions for their families.”
Mr. Brown was involved in the campaign this year to support the constitutional amendment on abortion, phone-banking alongside the Ohio Democratic Party and frequently bringing up the measure during campaign events.
Hours after Ohioans voted, Mr. Brown posted a video on social media that framed his three potential Republican challengers as sitting on the wrong side of the issue. “All of my opponents would support a national abortion ban,” the caption read.
If there was any doubt, Mr. Brown made clear in the interview that he saw the political benefit of the issue.
Abortion, he said, “will surely be talked about more than in my other races.”