Supreme Court justices privately said the abortion leak locked in their votes on overturning Roe v. Wade: report

• Supreme Court justices privately revealed the leak locked their votes in on the abortion case.
• That's according to CNN Joan Biskupic's reporting in her forthcoming book.

Last spring's unprecedented leak of a draft opinion that showed the Supreme Court was ready to overturn federal abortion rights ended up locking the justices' votes in place.

That's according to CNN Senior Supreme Court Analyst Joan Biskupic's reporting in her forthcoming book, "Nine Black Robes: Inside the Supreme Court's Drive to the Right and Its Historic Consequences," to be published April 4.

The Supreme Court heard oral arguments on the monumental case, Dobbs v. Jackson Women's Health Organization, in December 2021. At the time, a majority of the justices appeared open to upholding a Mississippi law that would ban abortion after 15 weeks of pregnancy, challenging the standard set in Roe v. Wade, which legalized abortion nationwide until around 24 weeks of pregnancy.

According to court procedure, the justices have to decide the case after hearing oral arguments. They typically meet in a private conference to share their views and cast an initial vote. Then, the most senior justice voting in the majority assigns another justice to write the opinion of the court.

The assigned justice drafts an opinion that is circulated among the justices, who must sign on to the ruling before it's publicly released. Internal discussions between the justices can sometimes result in a change to the vote and the opinion's language — deliberations that often take place in the weeks and months until a decision is handed down.

But on May 2, when Politico published a leaked draft opinion in the case, that debate stopped, Biskupic reported. The draft had circulated among the justices in February.

At the time, Chief Justice John Roberts, who was thought to have pushed for a middle ground approach in the case, had confirmed the authenticity of the draft and stressed that it wasn't the court's final decision.

But ultimately the court's draft opinion, authored by Associate Justice Samuel Alito, was virtually identical to the eventual June 24 opinion that overturned Roe v. Wade in a 5-4 vote.

Supreme Court investigators, after a months-long probe, failed to identify the source of the leak, according to report released in January.

A Supreme Court public information officer did not respond to Insider's request for comment.