In 2021, Representative Michelle Steel, a California Republican whose district President Biden won in 2020, cosponsored the Life at Conception Act, a bill to recognize a fertilized egg as a person with equal protections under the 14th Amendment.
It was a year before the Supreme Court would overturn Roe v. Wade. Ms. Steel was one of 166 House Republicans — then roughly three-quarters of the conference — who would ultimately sign on to the legislation, which amounted to a nationwide abortion ban. She did so just weeks after it was introduced.
For Republicans at the time, the sweeping potential impact of the bill was not seen as problematic. With Roe v. Wade, which recognized a constitutional right to an abortion as the law of the land, the measure could have little practical effect. It was mostly a gesture of support for the anti-abortion movement, a vital source of political backing for the G.O.P. And Democrats, who controlled the House at the time, would never bring it up for a vote anyway.
By last year, when House Republicans introduced identical legislation, the landscape had changed considerably. The Supreme Court’s ruling in Dobbs v. Jackson Women’s Health Organization overturned Roe, setting off a race by many states to impose severe restrictions, and abortion bans became a politically toxic issue for Republicans in elections across the country. The G.O.P. also was back in control of the House, if only narrowly, with the power to control what came to the floor.
Ms. Steel waited nearly a year to sign on — doing so on Friday morning, only after her Democratic challenger criticized her for flip-flopping on the issue for political gain and The New York Times notified her of a story documenting her change in position. Nearly three dozen other Republican lawmakers who supported it during the last Congress, including several who face tough re-election races in competitive districts, have yet to sign on again.
The shift reflects how dramatically the demise of Roe has changed the calculus for the G.O.P. on abortion, posing a dilemma for members of a party that still wants to appeal to conservative voters who favor severe restrictions without alienating a growing majority in the country that does not.
It also may signal the demise of a tactic Republicans in Congress have successfully employed for decades to score political points with their base: the anti-abortion messaging bill.
Speaker Mike Johnson, an evangelical Christian who has put his faith at the forefront of his politics throughout his career, has called abortion “an American holocaust.” But even he has conceded the political reality of the moment and said he was not pushing to bring contentious social issues to the floor this year.
Over the year and a half since the Dobbs decision, it has become clear to many Republicans that taking away a right that women have had for decades does not lead to a positive political outcome for them. About 69 percent of voters think abortion should be legal in the first three months of pregnancy, according to a recent Gallup poll, a record high.
Democrats have taken advantage of the dynamic, highlighting their efforts to protect abortion access and attacking Republicans who have previously sought to restrict or ban it — even if they have since inched away from their position or simply gone quiet on the issue.
“Steel will do what it takes to win,” said Derek Tran, a consumer rights lawyer and Democrat who is running to unseat Ms. Steel. “She’s staying quiet on abortion stuff, but she’s been nothing but an extremist in making sure abortion is eliminated as a right.”
While voters in other areas of the country may be worried about statewide laws or ballot measures restricting abortions, he added, in deep-blue California, “they are in fear of federal legislation.”
A spokeswoman for Ms. Steel, Claire Nance, criticized The Times for inquiring about whether the congresswoman had changed her position and said that Ms. Steel “is pro-life with the exceptions of rape, incest, and health of the mother.” The bill she endorsed on Friday does not include those exceptions.
Ms. Nance added of Ms. Steel, “Unlike her Democrat opponents, she does not support late-term abortion up until birth.” Mr. Tran describes himself as “100 percent pro-choice,” but has not endorsed such a policy.
The group of onetime cosponsors who have stayed away from the legislation this time around includes two other vulnerable Republican lawmakers from California who also represent districts Mr. Biden won in the last presidential election: Representatives David Valadao and Mike Garcia.
Representative Mariannette Miller-Meeks of Iowa, a former cosponsor of the bill who won her election in 2020 by six votes, has also stayed off the latest version. Two other Republicans whose districts Mr. Biden won in 2020, Representatives Don Bacon of Nebraska and David Schweikert of Arizona, have also not signed on this year, even though they supported the bill in the past.
Representative Nancy Mace, a Republican who represents a purple district in South Carolina, is also a previous cosponsor who has steered clear of the bill this time around, talking about how the party needs to have a more appealing message for female voters if it wants to keep control of the House.
Some former cosponsors have provided a reason for withholding their support this time around, and others have not. Mr. Bacon has said he does not support the 2023 legislation because it does not include a clear exception for the life of the mother. (The 2021 version that he backed also did not.)
When asked directly at an intimate town hall whether she planned to cosponsor the Life at Conception Act in this Congress as she had done in the past, Ms. Miller-Meeks said that “it has not come up yet,” then mentioned that most people define life as beginning between 12 and 15 weeks.
Mary Ziegler, a law professor and historian of abortion at the University of California, Davis, said Republicans have not changed their positions but some are simply tamping down on anti-abortion language and gestures they once embraced that they now believe could harm them politically.
“What they’re trying to do is accomplish things for the anti-abortion movement without broadcasting it, because they don’t want the political backlash,” Professor Ziegler said. “An empty-gesture messaging bill clearly seems like a bad idea.”
Still, even with the retreat from the legislation, more than 50 percent of House Republicans are backing the national abortion ban bill.
Nicole McCleskey, a G.O.P. pollster, said Republicans are still navigating through the new, politically thornier abortion landscape and that lawmakers from competitive districts were coming to understand the need to strike a balance between showing that they value women and remaining true to their principles.
“There are tweaks to how we represent our views, which are still consistent with the position on preserving life,” Ms. McCleskey said. “No one is going to vote for someone who says they will take away what they perceive to be their rights, but we have not yet fully recognized that in the way we talk about this issue.”
Ms. McCleskey said she advises Republicans to be consistent on abortion but to try to signal their regard for women by talking about other issues, like contraception, mental health care and care for older women.
Some Republicans are trying a version of that approach. Nikki Haley, the only woman in the G.O.P. presidential primary, has spoken of ensuring access to contraception, and Ms. Miller-Meeks has pointed to a contraception bill she introduced to try to blunt criticism of her opposition to abortion rights.
This week, two House committees began considering a measure entitled the Pregnant Students’ Rights Act, which would require colleges and universities to distribute information about the rights, accommodations and resources available to pregnant students.
Abortion rights advocacy organizations condemned the bill in a letter to members of Congress as “a thinly veiled anti-abortion law which would not address the key barriers to pregnant students’ educational attainment.” They argue the proposed bill seeks to limit pregnant students’ health care options by omitting abortion on the list of rights and services that it would require be made available to them.
Dana Singiser, co-founder of the nonprofit Contraception Access Initiative, said it was a savvy political move for Republicans to focus on smaller, seemingly palatable initiatives that on their face appear to enhance women’s rights, rather than curtail them.
“It’s now politically indefensible to support a national abortion ban,” she said. “This is the epitome of the dog that caught the car. They opposed abortion, the right gets overturned by the Supreme Court, and then they don’t know how to reconcile their extremist positions that were defensible so long as people actually had the right.”
Still, some Republicans are pushing as aggressively as ever for action on the issue.
“Protecting life is one of my top priorities in Congress,” said Representative Alex X. Mooney of West Virginia, the lead sponsor of the Life at Conception Act, who is running for Senate. “Respecting human life from the moment of conception until natural death is not simply a religious belief; it is a scientific fact that life begins at conception.”