Representative Jen Kiggans, a minivan-driving mother and Navy veteran, narrowly gained election final 12 months in her suburban Virginia swing district after a fiercely aggressive race that centered on her opposition to abortion rights.

The problem stays a high precedence for voters in her district, and showing too excessive on it may make her weak once more when she faces re-election in 2024. But Ms. Kiggans was one in every of dozens of Republicans from aggressive districts who voted this week to assist including a bevy of deeply partisan restrictions to the annual protection coverage invoice, together with one that may reverse a Pentagon coverage geared toward preserving entry to abortion providers for navy personnel, regardless of the place they’re stationed.

Democrats mentioned the G.O.P. provision was a steppingstone to instituting extra abortion bans throughout the nation, whereas Republicans argued it merely preserved a longstanding bar towards permitting federal funds for use to pay for abortions.

The vote put lawmakers like Ms. Kiggans, a high goal of Democrats whose seat is up for grabs in subsequent 12 months’s congressional elections, in a politically perilous place. And it raised the query of whether or not, in scoring the short-term victory of preserving his occasion united behind the annual protection invoice — which passed on a near-party-line vote on Friday — Speaker Kevin McCarthy might have embraced a method that might in the end price his occasion the House majority.

Ms. Kiggans and different equally located Republicans mentioned that they had no drawback backing the abortion restriction or the invoice itself, which emerged from the House loaded with different conservative coverage dictates, together with one barring the navy well being care program from offering transgender well being providers and one other limiting range coaching for navy personnel.

“Taxpayers should not be paying for elective surgery,” Ms. Kiggans, who ran as a reasonable centered on kitchen-table financial points, mentioned in an interview on Friday, explaining her vote. “This wasn’t a bill about abortion; it was about taxpayers paying for travel for military members for elective procedures.”

Still, Democrats’ House marketing campaign arm wasted no time in attacking Ms. Kiggans and different weak Republicans who had backed the invoice, and even some G.O.P. lawmakers conceded that embracing it was a foul search for a celebration attempting to broaden its attraction.

“The reason we’re in the majority today is because of swing districts and the reason we’re going to lose the majority is because of swing districts,” mentioned Representative Nancy Mace, Republican of South Carolina. “That’s just lost up here. We’re 10 days out from the August recess, and what have we done for women, post-Roe? Zero.”

Ms. Mace, who represents a politically break up district, railed towards the abortion modification however in the end voted for it as a result of she mentioned it was technically per Defense Department coverage. But she mentioned she regretted being pressured to take the vote in any respect.

“I’m not happy about it,” she mentioned. “I wish we didn’t have to do this right now.”

The Republican proposal would overturn a Defense Department coverage put in place after the Supreme Court struck down the constitutional proper to abortion final 12 months, setting off a rush by some states to enact curbs and bans on the process. The coverage reimburses journey prices for personnel who should journey out of state to acquire an abortion or associated providers. The coverage doesn’t present any cash for abortions.

Democrats pointed to the vote as a chief instance of Republicans taking votes that might in the end price them their House majority. Strategists in each events have prompt that the Supreme Court’s abortion choice, and Democrats’ subsequent efforts to highlight Republican opposition to abortion rights, weakened the G.O.P. throughout final 12 months’s election, costing them assist from impartial and suburban voters.

“For the swing districts they represent, they should be doing the opposite — but they’re not,” mentioned Courtney Rice, communications director for the Democratic Congressional Campaign Committee. “Their decision to put party politics over pocketbook issues is going to cost them the House in 2024.”

Many weak House Republicans mentioned they consoled themselves with the information that the amendments that centered on stoking battles on social points had been prone to be stripped out of the invoice by the Democrat-controlled Senate and wouldn’t be in a closing model of the protection coverage invoice.

“It wouldn’t be the way I would run the place, but at the end of the day as long as we pass N.D.A.A. like we’ve done and keep the really nasty poison pills out, I think it solves the problem,” mentioned Representative Tony Gonzales, Republican of Texas, referring to the protection invoice by the initials of its full identify. Mr. Gonzales, who voted for the abortion modification and others barring transgender well being providers and limiting range coaching for navy personnel, voted towards amendments that sought to chop funding for Ukraine.

Sarah Chamberlain, the president of the Republican Main Street Partnership, an outdoor group allied with the congressional Republican Main Street Caucus, described the vote as a “calculated risk” for a lot of members who gambled that it will not harm them politically.

“They made the decision that it was more important to them to get this bill out of the House than to fall on their sword on this one,” she mentioned. “They would have preferred these amendments didn’t exist, but I think they can defend their vote because they’re supporting the men and women of the military.”

Still, it’s not the primary time weak Republicans have caved to the onerous proper wing of their occasion, even when it means taking votes that might show to be political liabilities down the road. Mr. McCarthy, who has labored additional time to appease the precise flank whose assist he wants to stay in energy — most of whom signify protected G.O.P. districts — has completed comparatively little to guard extra mainstream Republicans whose seats are in danger from having to take powerful votes.

In April, they voted for Mr. McCarthy’s invoice to elevate the debt ceiling for one 12 months in alternate for spending cuts and coverage modifications, though it gutted packages that helped veterans and older individuals.

Last month, they voted in assist of a decision that may repeal a Biden administration rule that tightened federal rules on stabilizing braces for firearms which have been utilized in a number of mass shootings. House leaders introduced the invoice to the ground in order to help end a weeklong blockade by far-right Republicans.

Still, the extent of G.O.P. assist for the abortion modification — solely two Republicans, Representatives John Duarte of California and Brian Fitzpatrick of Pennsylvania, voted towards it — got here as a shock to Democrats.

“There are those across the aisle who realize that this is bad,” mentioned Representative Mikie Sherrill of New Jersey, a former Navy helicopter pilot who’s one in every of two Democratic ladies within the House who’ve served within the navy. Ms. Sherrill mentioned she had heard from some Republican colleagues who informed her privately, “‘This is a really bad idea, this is a mistake.’ Well then, why did everyone but two people vote for this really bad amendment?”

Representative Chrissie Houlahan, Democrat of Pennsylvania and a former Air Force officer, mentioned she was “surprised by the paucity of people who voted against the amendment. I was expecting 15 Republicans to do the right thing.”

Some extra mainstream Republicans sought to justify their votes by arguing that they weren’t voting towards abortion or transgender well being care — simply towards authorities funding for it.

“If you look at the polling, most Americans don’t think the federal government should be paying for abortions,” Representative Stephanie Bice, Republican of Oklahoma and vice chair of the Main Street Caucus, mentioned.

Representative Don Bacon, Republican of Nebraska, mentioned he backed the supply barring navy protection for gender transition surgical procedures and hormone remedy as a result of he believed, “If you want to do it, do it on your own dime.”

“I don’t think it should be the taxpayers’ responsibility,” Mr. Bacon added.