The outlet reports no draft decision in the court's modern history has ever been publicly disclosed while the case was still pending.
In the opinion, Justice Samuel Alito says the 1973 landmark decision guaranteeing constitutional protections of abortion rights, must be overruled. Alito, a member of the court's 6-3 conservative majority who was appointed by former President George W. Bush, went on to criticize the 1992 decision from Planned Parenthood versus Casey, which upheld the right to an abortion.
"Roe was egregiously wrong from the start. It's reasoning was exceptionally weak. And the decision has had damaging consequences," Alito wrote.
"We hold that Roe and Casey must be overruled," the draft opinion states.
The majority draft was written in response to the Mississippi case, Dobbs v. Jackson Women's Health Organization, which bans most abortions after 15 weeks of pregnancy.
Politico cautions the draft was written in February and may have already been re-written. And sometimes justices change their votes. FOX News nor KTVU has independently verified this draft opinion.
If Roe v. Wade is overturned, it would remove the federal guarantee of abortion protection and allow each state to set its own rules.
The court is expected to rule on the case before its term is up in late June or early July.
At arguments in December, all six conservative justices signaled that they would uphold the Mississippi law, and five asked questions that suggested that overruling Roe and Casey was a possibility. Only Chief Justice John Roberts seemed prepared to take the smaller step of upholding the 15-week ban, though that too would be a significant weakening of abortion rights.
Until now, the court has allowed states to regulate but not ban abortion before the point of viability, around 24 weeks.
House Speaker Nancy Pelosi and Sen. Chuck Schumer released a joint statement that read in part: "If the report is accurate, the Supreme Court is poised to inflict the greatest restriction of rights in the past fifty years – not just on women but on all Americans. The Republican-appointed justices' votes to overturn Roe v. Wade would go down as an abomination, one of the worst and most damaging decisions in modern history."
California Gov. Gavin Newsom posted reaction on Twitter, saying: "Our daughters, sisters, mothers and grandmothers will not be silenced. The world is about to hear their fury. California will not sit back. We are going to fight like hell." By late Monday evening, the governor along with members of the state legislature proposed an amendment to enshrine the right to choose in the California Constitution.
The statement was co-signed by President pro Tempore of the California Senate, Toni Atkins and Assembly Speaker Anthony Rendon.
"California will not stand idly by as women across America are stripped of their rights and the progress so many have fought for gets erased. We will fight. California is proposing an amendment to enshrine the right to choose in our state constitution so that there is no doubt as to the right to abortion in this state. We know we can’t trust the Supreme Court to protect reproductive rights, so California will build a firewall around this right in our state constitution. Women will remain protected here," the statement read.
Several states have prepared for this possible overturning of Roe v. Wade. "About two-dozen states have already passed what are called trigger laws, meaning that they're written in anticipation of Roe being overruled and the idea is that they would immediately come into effect in those states and would ban abortion in all those states. So within days, we would have half of the states would have lost their right to an abortion," UC Hastings Law Professor David Levine said. He suspects the leak is possibly the first or an early draft of the opinion.
Equality California says the latest estimate from the Guttmacher Institute, a reproductive health research group that supports abortion rights, found that nearly one in four women will obtain an abortion by age 45.
"Planned Parenthood health centers across California will remain open. They will remain willing to help. And we will do all we can to continue to provide abortion services to all who need it or seek it here in California," said Jodi Hicks, president and CEO of Planned Parenthood Affiliates of California.
Sixteen states and the District of Columbia, meanwhile, have protected access to abortion in state law.
The Associated Press contributed to this report.