WASHINGTON — Sen. Susan Collins, R-Maine, a key swing vote on President Donald Trump’s next Supreme Court pick, said Sunday that she would not vote for any judge who wanted to end access to abortion in the United States by overturning Roe v. Wade.

“I would not support a nominee who demonstrated hostility to Roe v. Wade,” Collins said Sunday on CNN’s “State of the Union,” adding that Roe v. Wade established abortion as a “constitutional right.”

In another appearance, on ABC News’s “This Week,” Collins said that any judge who wants to overturn Roe has an “activist agenda” that she thinks goes against the fundamental tenets of U.S. law and the Constitution.

Trump has already met with Collins to discuss potential candidates for the Supreme Court, and she said she let him know that she would not support some of the people on the list of 25 judges he’s considering for the critical role on the nation’s highest court. She said she urged him to expand his list.

On the 2016 campaign trail, Trump indicated that he would take into account whether a judge would overturn Roe v. Wade when he considered them for a Supreme Court position, but he has changed his rhetoric in the past week after Justice Anthony M. Kennedy announced his retirement.

Collins said Trump assured her that he would not ask nominees whether they would vote to overturn Roe v. Wade.

“The president told me in our meeting that he would not ask that question,” she said on CNN. In her ABC News appearance, Collins added that she feels it would be “inappropriate” for Trump to ask that question.

Supreme Court nominees must be confirmed by a majority in the U.S. Senate. Republicans have 51 votes, so anything more than one defection would sink a nominee unless a Democrat crossed party lines. Collins and Lisa Murkowski, R-Alaska, are widely considered the critical swing voters. Both women bucked Trump by voting against the health-care overhaul bill last summer, and they have tended to support access to abortion.

Sen. Amy Klobuchar, D-Minn., a member of the Senate Judiciary Committee, appeared just after Collins on “This Week” and called her Republican colleague’s remarks in support of Roe v. Wade “very heartening.”

Trump has said that he views picking Supreme Court justices as the most important thing he will do as president outside of war and peace. He said at a rally in North Dakota last week that he wants to pick someone who will “be there for 40, 45 years.”

Sen. Susan Collins, R-Maine, said Sunday any judge who wants to overturn Roe v. Wade has an “activist agenda.” (Melina Mara, The Washington Post)