Supreme Court Justice Ruth Bader Ginsburg has a surprising confession: She "wasn't 100 percent sober" when she fell asleep at the president's State of the Union address last month. 

Ginsburg told an audience Thursday night that she drank some wine at dinner before attending the annual speech, where cameras repeatedly caught her nodding off. 

The 81-year-old jurist said she had dined with Justice Anthony Kennedy and couldn't resist "the very fine California wine" he brought. 

"The audience for the most part is awake, because they're bobbing up and down, and we sit there, stone-faced. But we're not, at least I wasn't, 100 percent sober," Ginsburg said to laughter and applause during a joint appearance with Justice Anthony Scalia at George Washington University. 

Ginsburg, who acknowledged dozing at the speech in past years, said she tried to resist the wine and stick to sparkling water, but to no avail. 

"In the end, the dinner was so delicious it needed wine," she said. 

In previous years, she said it helped that former Justice David Souter would keep an eye on her. 

"When he was on the court, he was on one side and he had acute sense of when I was about to, so he would give me a pinch," she said. "Now I have Justice Kennedy on one side and Justice (Stephen) Breyer and they are sort of timid about that thing." 

After she got home, Ginsburg said she got a call from one of her granddaughters. "She said, `Bubbe, you were sleeping at the State of the Union!"' 

The comments came in a talk sponsored by the Smithsonian Associates and moderated by National Public Radio's Nina Totenberg. 

Her confession prompted some gentle ribbing from Scalia, who makes it a habit to skip the president's annual address to Congress. 

"Serves you right, I say, serves you right for going," he teased Ginsburg. 

Scalia said he stopped going years ago to escape what he called "a childish spectacle." 

"One side jumps up and the other side jumps up and we sit there, you know, like bumps on a log," Scalia said.