For decades, Americans had settled around an uneasy truce on abortion. Even if most people weren’t happy with the status quo, public opinion about the legality and morality of abortion remained relatively static. But the Supreme Court’s decision last summer overturning Roe v. Wade set off a seismic change, in one swoop striking down a federal right to abortion that had existed for 50 years, long enough that women of reproductive age had never lived in a world without it. As the decision triggered state bans and animated voters in the midterms, it shook complacency and forced many people to reconsider their positions.

In the year since, polling shows that what had been considered stable ground has begun to shift: For the first time, a majority of Americans say abortion is “morally acceptable.” A majority now believes abortion laws are too strict. They are significantly more likely to identify, in the language of polls, as “pro-choice” over “pro-life,” for the first time in two decades.

And more voters than ever say they will vote only for a candidate who shares their views on abortion, with a twist: While Republicans and those identifying as “pro-life” have historically been most likely to see abortion as a litmus test, now they are less motivated by it, while Democrats and those identifying as “pro-choice” are far more so.

One survey in the weeks after the court’s decision last June found that 92 percent of people had heard news coverage of abortion and 73 percent had one or more conversations about it. As people talked — at work, over family Zoom calls, even with strangers in grocery store aisles — they were forced to confront new medical realities and a disconnect between the status of women now and in 1973, when Roe was decided.

Many found their views on abortion more complex and more nuanced than they realized. Polls and interviews with Americans show them thinking and behaving differently as a result, especially when it comes to politics.

“This is a paradigm shift,” said Lydia Saad, director of United States social research for Gallup, the polling firm. “There’s still a lot of ambivalence, there aren’t a lot of all-or-nothing people. But there is much more support for abortion rights than there was, and that seems to be here to stay.”

Gallup happened to start its annual survey of American values just as the court’s decision in the case, Dobbs v. Jackson Women’s Health Organization, leaked last May. That was when the balance began to tilt toward voters identifying as “pro-choice.” And when the question was divided into whether abortion should be legal in the first, second or third trimester, the share of Americans who say it should be legal in each was the highest it has been since Gallup first asked in 1996.

The New York Times reviewed polls from groups that have been asking Americans about abortion for decades, including Gallup, Public Religion Research Institute, Pew Research, Ipsos, KFF and other nonpartisan polling organizations. All pointed to the same general trends: growing public support for legalized abortion and dissatisfaction with new laws that restrict it.

Pollsters say the biggest change was in political action around abortion, not necessarily in people’s core views. Polls regarding whether abortion should be legal or illegal in most or all cases — long the most widely-used metric — have remained relatively stable, with the percentage of voters saying abortion should be legal in all or most cases slowly ticking up over the past five years to somewhere between 60 percent and 70 percent.

And generally, most Americans believe abortion should be limited, especially in the second and third trimesters — not unlike the framework established by Roe.

But there were sudden and significant jumps in support for legalized abortion post-Dobbs among some groups, including Republican men and Black Protestants. Polling by the Public Religion Research Institute found that the percentage of Hispanic Catholics saying abortion should be legal in all cases doubled between March and December of last year, from 16 percent to 31 percent. And the share of voters saying abortion should be illegal in all cases dropped significantly in several polls.

That largely reflected the dramatic change in abortion access. Fourteen states enacted near-total bans on abortion as a result of the court’s decision.

News stories recounted devastating consequences: Women denied abortions despite carrying fetuses with no skull; a 10-year-old pregnant by rape forced to cross state lines for an abortion; women carrying nonviable pregnancies who could not have an abortion until they were on the brink of death.

“While Roe was settled law, you kind of didn’t have to worry about the consequences,” said Mollie Wilson O’Reilly, a writer for Commonweal, the Catholic lay publication, and the mother of four. “You could say, ‘I think abortion should be illegal in all circumstances,’ if you didn’t really have to think about what it would mean for that to happen.”

Raised in the church and still active in her parish, Ms. O’Reilly, 42, embraced its teachings that abortion was equivalent to murder, as part of a broader church doctrine on the protection of life that also opposes capital punishment and mistreatment of migrants.

Her evolution to supporting abortion rights started two years ago when she had a miscarriage that required emergency dilation and curettage; only when she saw her chart later did she realize the term was the technical name for abortion.

“When people have the idea that abortion equals killing babies, it’s very easy to say, ‘Of course I’m against that,’” she said. “If you start seeing how reproductive health care is necessary to women, you start to see that if you’re supporting these policies that ban abortion, you’re going to end up killing women.”

She wrote about her experience and joined other Catholic women, largely writers and professors, in publicizing an open letter to the Catholic church, declaring that “pro-life” policies centered on opposition to abortion “often hurt women.” They called on the church and elected officials to embrace “reproductive justice” that would include better health care and wages for pregnant women and mothers.

Ms. Wilson O’Reilly now believes decisions on abortion should be up to women and their doctors, not governments. It’s impossible to draw a “bright line” around what exceptions to the bans should be allowed, she said.

Still, she doesn’t call herself a “pro-choice Catholic”: “I think you can hold the view that a developing life is sacred and still not feel that it is appropriate or necessary to outlaw abortion.”

In a poll by KFF, the health policy research firm, a plurality of Americans — four in ten — and more among Democrats and women, said they were “very concerned” that bans have made it difficult for doctors to care for pregnant women with complications. Gallup found Americans more dissatisfied with abortion laws than at any point in 22 years of measuring the trend, with new highs among women, Catholics and Protestants saying the laws are “too strict.”

A Pew poll in April concluded that views on abortion law increasingly depend on where people live: The percentage of those saying abortion should be “easier to get” rose sharply last year in states where bans have been enacted or are on hold because of court disputes.

In South Carolina, which recently banned abortion at six weeks of pregnancy, Jill Hartle, a 36-year-old hairdresser, had only ever voted Republican. She called herself “pro-choice,” she said, but did not think about how that collided with the party’s opposition to abortion, even though she considered herself an informed voter, and her family talked politics regularly.

She became pregnant shortly before the court’s decision to overturn Roe. At 18 weeks, anatomy scans determined that the fetus had a heart defect that kills most infants within the first two weeks of life, one that Ms. Hartle knew well because it had killed her best friend’s child.

At the time, her state’s legislature was debating a ban. “The first words the doctor said were, ‘There are things I can discuss with you today that I may not be able to discuss with you tomorrow or in a week because our laws are changing so rapidly in South Carolina,’” she said.

Ms. Hartle and her husband ended up traveling to Washington for an abortion.

People, she said, told her she could not be a Christian and have an abortion; others said what she had was “not an abortion” because her pregnancy was not unwanted. After she recovered, she started a foundation to fight against what it calls the “catastrophic turnover” of Roe and to help other women find abortions. She began testifying against proposed bans and campaigning for Democratic candidates.

“I want to tell people it’s OK to vote against party lines,” she said.

South Carolina legislators passed the state’s ban in May, over the opposition of a small group of female legislators, both Republican and Democrat. Polls show that the state’s voters oppose the ban, but as in many states, legislative districts are gerrymandered and seats often go uncontested, so Republican lawmakers are often more concerned about a primary challenge from the right than a general election fight.

Groups that oppose abortion rights emphasize that most Americans want restrictions on abortion — and indeed, just 22 percent of Americans in Gallup’s poll said abortion should be legal in the third trimester.

“People will react to a once-in-a-generation event. That’s true, and it should be a wake-up call for Republicans,” said Marjorie Dannenfelser, president of Susan B. Anthony Pro-Life America, which was founded to help elect lawmakers who oppose abortion rights. Republicans, she said, have to paint Democratic candidates as the extremists on abortion: “If they don’t, they may very well lose.”

A coalition of Republicans and evangelicals has waged a four-decade campaign to end abortion, but the number of Americans identifying as evangelical has declined sharply. And polls on abortion suggest political dynamics may be shifting.

High proportions of women ages 18 to 49, and especially Democrats, say they will vote only for candidates who support their views on abortion. On the flip side, Republicans are less enthusiastic. The Public Religion Research Institute found that the share of Republicans who think abortion should be illegal in all or most cases and who said they would vote only for a candidate whose view matched their own had dropped significantly, to 30 percent last December from 42 percent in December 2020.

“That’s a direct effect of Dobbs,” said Melissa Deckman, the chief executive of PRRI and a political scientist.

“Does it mean that suddenly Republicans will change their minds about abortion? No, partisans vote for partisans,” she said. “But this is an issue of salience and turnout.”

John Richard, a 73-year-old disabled Vietnam veteran who lives in the swing district of Bucks County, Pa., said he had always voted Republican until he became a “Never Trumper.” The court’s decision in Dobbs made him go so far as to switch his voter registration to Democrat.

“If my daughters came to me and said they want an abortion, I’d try and talk them out of it,” Mr. Richard, a retired supermarket manager, said. “But I don’t think anyone has the right to tell you how to control your own body. I fought in a war for that. I didn’t do that for no reason.”

Asked in polls to name their biggest concern, most people still don’t say abortion. But in polls and in interviews, many relate abortion rights to other top concerns: about dysfunctional government, gun violence, civil rights and income inequality.

“It’s not enough anymore to ask what people think about abortion, because to them abortion is part of a larger set of concerns about the country,” said Tresa Undem, whose firm conducts polls for businesses as well as for Democratic-leaning groups.

Starting with the leak and ending after the midterm elections last year, Ms. Undem conducted three surveys that tracked engagement with the issue by how many ads people saw, conversations they had and what concerns they raised about abortion.

Increasingly, people mentioned concerns about losing rights and freedoms, the influence of religion in government, threats to democracy, as well as maternal mortality and whether they want to have more children.

The biggest change in polls has been the swing in who votes on abortion. In the most recent example, Gallup found that in 2020 roughly 25 percent of Democrats and Republicans alike had said they would vote only for a candidate who shared their view on abortion. The share of Democrats saying this has jumped since the leak of the Dobbs decision, to 41 percent. Among Republicans the percentage was down slightly.

In San Antonio, Sergio Mata, a 31-year-old artist, said he was shocked when Texas passed a ban on abortion in 2021, and by how much anti-abortion sentiment he suddenly heard around him. As a gay man and the American-born son of Mexican immigrants, he fears that gay rights will be reversed and birthright citizenship will be taken away: “I kind of feel what will happen if my existence gets illegal.”

He considers himself a Democrat, but the overturning of Roe, he said, “pushed me to be more extreme,” he said. That meant paying more attention to the news and voting in the midterm elections for the first time.

In Portland, Ore., Ruby Hill, who is Black, said she had been alarmed at the flourishing of the Proud Boys and other white supremacist groups around her. She lives not far from where two members of an extremist gang ran over a 19-year-old Black man with a Jeep in 2016. Ms. Hill, also a Democrat, said she was then redistricted into a largely white congressional district represented by a Republican.

The Dobbs decision, she said, made her start recruiting supporters of abortion rights among her friends, her grandchildren and their friends, and family members in Tennessee and California and Virginia over a weekly Zoom, “so they can convince people they know to stand up for more rights before more get taken from us,” she said. “If they got away with this and they feel that nobody cares, it’s more rights they are going to proceed to take away — civil rights, voting rights, abortion, birth control, it’s all part of that one big package. If you sit on the sideline, it says that you think it’s OK.”