ADEL, Iowa (AP) — Kirsten Gillibrand is promising that, if elected president, she’ll only appoint Supreme Court justices who will support the Roe v. Wade decision, imposing a key legal litmus test that’s consistent with most Democrats’ values but which White House contenders don’t usually express so openly.

The Democratic senator from New York writes in a Tuesday Medium post that Republican-led legislatures in 28 states have attempted to impose deep abortion restrictions this year. To reverse that, she said, “As president, I will only nominate judges?_?including Supreme Court justices?_?who will commit to upholding Roe v. Wade as settled law and protect women’s reproductive rights.”

The 1973 Roe v. Wade ruling established a woman’s constitutional right to abortion.

Gillibrand acknowledged that “traditionally, presidents and presidential candidates haven’t drawn lines in the sand on judicial appointments, to preserve the impartiality of our judiciary.” But she countered that Senate Majority Leader Mitch McConnell refused to consider President Barack Obama’s 2016 high court nomination of Merrick Garland, citing the then-upcoming presidential election.

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“That tradition ended when Mitch McConnell obstructed the nomination process and stole a Supreme Court seat, when Donald Trump nominated dozens of ideologically extreme judges hand-picked by far-right think tanks, and when Republicans confirmed a Supreme Court Justice who is credibly accused of sexual misconduct,” Gillibrand wrote. That’s a reference to Brett Kavanaugh’s successful confirmation to the high court by the Senate last year, after he was nominated by Trump. Kavanaugh denied the allegations.

Gillibrand further wrote, “I believe that reproductive rights are human rights, and they are nonnegotiable.”

She’s one of the Senate’s most vocal members on issues of sexual harassment, military sexual assault, equal pay for women and family leave, and has made supporting the #MeToo movement a centerpiece of her campaign. But Gillibrand has struggled to raise money and trails other Democratic presidential candidates in early public opinion polls ahead of the 2020 election.

The Supreme Court has already become an issue for Democrats on the presidential campaign trail. White House hopefuls California Sen. Kamala Harris, Sen. Elizabeth Warren of Massachusetts and former Texas Rep. Beto O’Rourke have said they’d be willing to consider expanding the court past its nine current judges to counter what they call its conservative basis, as has Mayor Pete Buttigieg of South Bend, Indiana.

But Gillibrand is the first to publicly declare that she will only consider nominating pro-abortion rights judges.