California, a U.S. trendsetter for progressive policies and a state where the current governor once made news issuing marriage licenses to same-sex couples in San Francisco before it was legal, will attempt to enshrine marriage equality in the state constitution.

The effort comes 15 years after a voter-approved initiative, called Proposition 8, banned the state from recognizing same-sex marriages. In 2013, the U.S. Supreme Court cleared the way for same-sex marriage in California. The constitutional amendment is still on the books, however, and that worries advocates who think the high court may revisit the 2015 case that legalized gay marriage nationwide.

“It’s absolute poison, it is so destructive and it’s humiliating that this is in our constitution,” said Democrat Scott Wiener, a state senator who represents San Francisco.

He and Democratic Assembly Member Evan Low of Silicon Valley plan to introduce legislation Tuesday to rescind Proposition 8. The measure would need to be approved in the Legislature by a two-thirds vote, and then it will ultimately fall to voters to decide via a referendum.

In the days leading up to Proposition 8′s approval, Low joined opponents of the measure outside his alma mater De Anza College in Cupertino to call on voters to reject the initiative. When it passed, it felt personal to Low, who is gay.

“Why do fellow Californians hate me?” he said. “Why do they feel that my rights should be eliminated?”

California could follow in the footsteps of Nevada, which in 2020 became the first state to amend its constitution to ensure the right to same-sex marriage. The matter took on fresh urgency last year when the U.S. Supreme Court overturned the right to an abortion established by Roe v. Wade. At the time, Supreme Court Justice Clarence Thomas called into question other prominent cases and urged the court to reconsider them. His list included Obergefell v. Hodges, which forced states to issue and recognize same-sex marriages.

“In future cases, we should reconsider all of this Court’s substantive due process precedents, including Griswold, Lawrence, and Obergefell,” Thomas wrote, referencing two other landmark cases involving access to birth control and a decision striking down laws against same-sex sexual activity.

In December, President Joe Biden signed into law the Respect for Marriage Act, which requires states to recognize same-sex marriages, but the legislation doesn’t force states to allow them if Obergefell is overturned.

Wiener and Low, the two California lawmakers, hope to replicate the process under which state voters in November approved a constitutional change guaranteeing the right to abortion.

Proposition 8 has yet to be repealed because there was less urgency to do so after the state was allowed to resume issuing marriage licenses to same-sex couples and gay marriage was legalized nationwide, Wiener said.

“It became a fire drill once the Supreme Court overturned Roe v. Wade,” he said.

The path to marriage equality in the Golden State was uneven. In 2000, voters approved a statute that banned the recognition of same-sex marriages, a measure that was overturned by the courts. Gov. Gavin Newsom, a Democrat who became San Francisco’s mayor in 2004, issued marriages in the city to same-sex couples in a move that defied the law and ran counter to views then held by many in his party. In 2005, the California Legislature was ahead of all other states when it passed a bill to legalize same-sex marriage. But then-Gov. Arnold Schwarzenegger, a Republican, vetoed it.

Support for marriage equality has rapidly expanded since the Obergefell ruling. While Mormon groups helped fund the Proposition 8 campaign in California, the Church of Jesus Christ of Latter-day Saints came out in support of the Respect for Marriage Act.

Tony Hoang, executive director of Equality California, is optimistic the group can help build a large supportive coalition for the proposed amendment.

“I know this will be a bipartisan campaign,” he said.