Vermont legislators will vote Tuesday on a constitutional amendment that would guarantee the right to abortion and contraception, the first amendment of its kind anywhere in the United States.

If passed, the proposed amendment, known as Proposition 5, will head to Gov. Phil Scott, R, who is required to give public notice of the measure before it appears on the ballot in November. Scott has signaled his support for Proposition 5. And voters in Vermont, where 70 percent of people say abortion should be legal in all or most cases, are expected to approve it.

The proposal is part of a wave of abortion rights legislation to emerge in Democratic states this year, ahead of a key Supreme Court ruling on abortion expected this summer. The Supreme Court case, which involves a Mississippi law that bans abortion at 15 weeks, could overturn or significantly weaken Roe v. Wade, the landmark decision that has guaranteed the right to abortion for almost 50 years.

Fifteen states have passed laws protecting the right to abortion, including, most recently, New Jersey, where Gov. Phil Murphy, D, signed the Freedom of Reproductive Choice Act in January. Other states, such as Florida, have privacy laws in their state constitutions, which courts have interpreted to protect the right to abortion. But no other state has enshrined the right to abortion in its constitution.

At a moment when antiabortion legislators across the Southeast and Midwest are proposing dramatic rollbacks of abortion rights, abortion rights advocates are thrilled to see a state moving in the opposite direction.

"We are hoping to be a model for other states to follow," said Lucy Leriche, vice president of Vermont Public Policy at Planned Parenthood of Northern New England. "In states all over the country, politicians are moving to take away reproductive rights, specifically abortion rights, and we could be an example of another way."

Republican lawmakers and lobbyists in Vermont have called the amendment "extreme." By adding this amendment to the state constitution, said Republican state Rep. Anne Donahue, legislators are making the assumption that public opinion on abortion won't change.

"We as human beings have made a lot of mistakes at times when we thought we were doing the right thing," said Donahue, who cited the Supreme Court's prior rulings on segregation and eugenics. "When we start putting a current belief in the constitution, I think we're playing with fire."

Donahue and other Republicans have cited concerns with certain language in the proposed amendment. Proposition 5 guarantees the right to "reproductive autonomy," a term Donahue said is too vague, opening the door for future courts to interpret the amendment more broadly than legislators intended.

The amendment, which passed both the House and Senate in 2019 and was approved again in the Senate in 2021, has been "a lot of work and a long haul," said Leriche. Proposition 5 gained more momentum, she said, when the Supreme Court indicated its willingness to reconsider Roe v. Wade in oral arguments in December.

When Leriche first raised the idea of a constitutional amendment for abortion rights in 2018, she said, some in Vermont dismissed it as unnecessary.

"A lot of people I would consider strong supporters of reproductive rights said, 'This is Vermont; nothing bad is going to happen here,'" she said. "Now there are people coming to me, saying, 'Wow ... I can't believe the Supreme Court is poised to overturn Roe.'"

Democratic lawmakers in other states are backing different kinds of laws to protect abortion rights ahead of the Supreme Court's decision. California, for example, is positioning itself as an "abortion sanctuary" for people who need abortion care in antiabortion states.

California state Sen. Nancy Skinner, D, will soon introduce a bill to create a centralized database for people traveling to the state for abortions, which would help connect them with services and funding sources. Another bill introduced in California this session would offer civil protections for California-based abortion providers who serve patients from other states.

"California will not just stand by," Skinner said at a Jan. 20 news conference. "We are committed to protecting and providing access to abortion and all reproductive services, not only for Californians, but any who seek refuge here."