Washington (AFP) – President Joe Biden urged voters Tuesday to defend their “fundamental” rights after a leaked Supreme Court draft on ending nationwide legal abortion sparked a political firestorm around one of America's most divisive ethical issues.

If confirmed by the court, the ruling would categorically overturn the 1973 Roe v. Wade case, which enshrined abortion rights across the country — ensuring the hot-button question will dominate the November midterm elections for control of Congress.

In practice, it would mean that abortion laws were left up to individual state legislatures, with as many as half of the country's states expected to introduce bans or new restrictions.

Abortion is the fiercest fought of all the so-called culture war battles, and Republicans have pushed hard for years to overturn Roe — something that became almost inevitable once three conservative justices were appointed under Donald Trump, shifting the Supreme Court's political balance sharply to the right.

Biden, whose Democrats have been forecast to lose their narrow control of Congress in November, issued a rallying cry to the left, warning that restricting abortion rights will be only the beginning.

“I believe that a woman's right to choose is fundamental… and basic fairness and the stability of our law demand that it not be overturned,” Biden said in a written statement.

“It will fall on voters to elect” officials who back abortion rights, he said, vowing to work to pass legislation in Congress that codifies Roe v. Wade — a goal impossible to achieve unless far more Democrats win seats.

Speaking to reporters, Biden went further, calling the draft ruling “radical” and warning of a “fundamental shift in American jurisprudence” that could put into question the future of gay marriage and “how you raise your child.”

“It would mean that every other decision relating to the notion of privacy is thrown into question.”

‘Roe v. Wade is going to go!'

The leaking of the draft ruling was unprecedented, knocking another hole in the once hallowed reputation of the top court as the one apolitical branch in the US government.

Chief Justice John Roberts confirmed that the document released by the Politico news website was authentic, although he cautioned that this did not necessarily represent the court's final decision. Roberts ordered a probe into the leak.

Crowds of protesters from both camps descended on the Supreme Court building, with anti-abortion activists chanting “abortion is violence. Abortion is oppression” as well as “Hey Hey Ho Ho Roe v. Wade is going to go!”

In Roe v. Wade, the court ruled that access to abortion is a constitutional right. In a subsequent 1992 ruling, Planned Parenthood v. Casey, the court guaranteed a woman's right to an abortion until the fetus is viable outside the womb, which is typically around 22 to 24 weeks of gestation.

Most developed countries allow abortions on request up to a gestational limit, most often 12 weeks. 

Roe v. Wade makes the United States one of a handful of nations to allow the procedure without restriction beyond 20 weeks of pregnancy — although many others allow it past that point for specific reasons.

The court had been expected to decide this June on challenges to Roe v. Wade.

The Republican National Committee said it was time for abortion decisions to revert to state governments.

“The far left wants unelected judges to impose a radical, one-size fits all abortion policy, leaving Americans without a voice. The Republican Party will always stand for the sanctity of life,” it said.

‘Wrong from the start'

The draft opinion was written by Justice Samuel Alito and according to Politico has been circulating since February inside the court — now dominated 6-3 by conservatives.

The 98-page draft majority opinion calls Roe v. Wade decision enshrining the right to abortion “egregiously wrong from the start.”

“We hold that Roe and Casey must be overruled,” Alito writes in the document, labeled the “Opinion of the Court.”

“It is time to heed the Constitution and return the issue of abortion to the people's elected representatives.”

The Guttmacher Institute, which backs abortion rights, has said 26 states are “certain or likely” to ban abortion if Roe v. Wade is overturned.

Democratic governors of several states including California, New Mexico and Michigan swiftly announced plans to enshrine abortion rights into law even if the court overturns Roe, with California Governor Gavin Newsom tweeting: “Women will remain protected here.”