Biden admonishes the Supreme Court for overturning Roe v. Wade

In his third State of the Union address Thursday, Joe Biden did what was once unthinkable: directly challenge Supreme Court justices about one of their opinions, addressing them personally.

Biden brought up the conservative majority’s landmark reversal of Roe v. Wade. He had begun to read an excerpt of the decision when he began a brief aside, looking right at the justices sitting in the front row.

“With all due respect, justices, women are not without ... electoral or political power," he said.

Then, in what appeared to be an ad-libbed moment, he added, "You’re about to realize just how much …” before Democrats in the chamber jumped to their feet and cheered.

The justices, dressed in their traditional black robes, sat expressionless but looking forward as the applause and reaction thundered around them. Secretary of State Antony Blinken, who was among those sitting beside the group, stood to applaud.

It rare to see any interaction between a president and the Supreme Court justices, but in 2010, conservative Justice Samuel Alito appeared to mouth "not true" or "simply not true" when President Barack Obama criticized the court's ruling in Citizens United, removing corporate campaign spending limits.

Alito has not attended a State of the Union address since then.

Biden hit on several themes related to women's reproductive rights, including an Alabama Supreme Court decision that has caused mass confusion in the state over in vitro fertilization.

This article was originally published on NBCNews.com