NEW YORK — A solid majority of Americans believe most abortions should be legal in the first three months of a woman’s pregnancy, but most say the procedure should usually be illegal in the second and third trimesters, according to a new poll.

The poll comes just weeks after the U.S. Supreme Court agreed to hear a case involving a currently blocked Mississippi law that would ban abortions after 15 weeks of pregnancy, two weeks into the second trimester. If the high court upholds the law, it would be the first time since the 1973 Roe v. Wade decision confirming a woman’s right to abortion that a state would be allowed to ban abortions before a fetus can survive outside the womb.

The new poll from The Associated Press-NORC Center for Public Affairs Research finds 61 percent of Americans say abortion should be legal in most or all circumstances in the first trimester of a pregnancy. However, 65 percent said abortion should usually be illegal in the second trimester, and 80 percent said that about the third trimester.

Still, the poll finds many Americans believe that the procedure should be allowable under at least some circumstances even during the second or third trimesters. For abortions during the second trimester, 34 percent say they should usually or always be legal, and another 30 percent say they should be illegal in most but not all cases. In the third trimester, 19 percent think most or all abortions should be legal, and another 26 percent say they should be illegal only in most cases.

Michael New, an abortion opponent who teaches social research at Catholic University of America, predicted the findings regarding second- and third-trimester abortions will be useful to the pro-life movement.

“This helps counter the narrative that the abortion policy outcome established by the Roe v. Wade decision enjoys substantial public support,” he said.

David O’Steen, executive director of the National Right to Life Committee, said the findings suggest that abortion rights advocates are “way out of the public mainstream” to the extent that they support abortion access even late in pregnancy.

But Dr. Daniel Grossman, a professor of obstetrics and gynecology at the University of California, San Francisco, who supports abortion rights, cited research showing that Americans viewed second-trimester abortions more empathetically when told about some of the reasons why women seek them.

These include time-consuming difficulties making arrangements with an abortion clinic and learning during the second trimester that the fetus would die or have severe disabilities due to abnormalities, Grossman said.

“More work needs to be done to elevate the voices of people who have had abortions and who want to share their stories to help people understand the many reasons why this medical care is so necessary,” he said via email.

Majorities of Americans — Republicans and Democrats alike — think a pregnant woman should be able to obtain a legal abortion if her life is seriously endangered, if the pregnancy results from rape or incest or if the child would be born with a life-threatening illness.

Americans are closely divided over whether a pregnant woman should be able to obtain a legal abortion if she wants one for any reason, 49 percent yes to 50 percent no.

Jenny Ma, senior staff attorney with the Center for Reproductive Rights, said women seeking second-trimester abortions included disproportionately high numbers of young people, Black women and women living in poverty. Some had not learned they were pregnant until much later than the norm; others had trouble raising the needed funds to afford an abortion, Ma said.

She noted that Republican-governed states have enacted numerous restrictions in recent years that often complicated the process for getting even a first-trimester abortion.

“Removing the many existing barriers to earlier abortion care would reduce need for second- and third-trimester abortions,” Ma said.

Abortions after the first trimester are not rare, but they are exceptions to the norm. The Centers for Disease Control and Prevention, in its most recent report on abortion in the U.S., estimated that 92 percent of the abortions in 2018 were performed within the first 13 weeks of pregnancy.

The poll also shows how opinions on abortion diverge sharply along party lines. Roughly three-quarters of Democrats think abortion should be legal in all or most cases; about two-thirds of Republicans think it should be illegal in all or most cases.

But most Americans fall between extreme opinions on the issue. Just 23 percent say abortion in general should be legal in all cases, while 33 percent say it should be legal in most cases. Thirty percent say abortion should be illegal in most cases; just 13 percent say it should be illegal in all cases.

Respondents from three major religious groups — white mainline Protestants, nonwhite Protestants and Catholics — are closely divided as to whether abortion should usually be legal or illegal in most cases. It was different for white evangelicals — about three-quarters of them say abortion should be illegal in all or most cases.

Dave Steiner, a hotel manager from suburban Chicago, was among those responding to the AP-NORC poll who said abortion should be legal in the first trimester but generally illegal thereafter.

“I was raised a very strict Catholic — abortion was just no, no, no,” said Steiner, 67. “As I became more liberal and a Democrat, I felt the woman should have the right to choose — but that should be in the first trimester.”

“Abortions are going to happen anyway,” he added. “If you’re making it illegal, you’re just chasing it underground.”

Fingerhut reported from Washington. Associated Press video journalist Hillary Powell in Washington contributed to this report.

The AP-NORC poll of 1,125 adults used a sample drawn from NORC’s probability-based AmeriSpeak Panel, which is designed to be representative of the U.S. population. The margin of sampling error for all respondents is plus or minus 4.2 percentage points.