Supreme Court Justice Ruth Bader Ginsburg has become a cultural force — her face emblazoned on T-shirts and tattoos, her iconic status solidified with the hip-hop-inspired moniker Notorious RBG. But, she's also developed a bit of a reputation for snoozing away during annual State of the Union addresses.

Ginsburg says there's a perfectly valid reason: alcohol.

Like co-workers everywhere, the justices of the nation's highest court enjoy bonding through food and wine. And a pre-State of the Union Address dinner, complete with wine, has become a tradition for the justices, Ginsburg explained Wednesday during a talk about the court's food culture at the National Museum of American History in Washington, D.C.

"One year, Justice [Anthony] Kennedy came with a couple of bottles of Opus One from California," Ginsburg said. "That was the first time I fell asleep during the State of the Union."

According to Supreme Court curator Catherine Fitts, civility enforced through food has been woven into the fabric of the court since its earliest days.

In the early 1800s, when Washington, D.C., was newly minted as the nation's capital, the Supreme Court was in session for only a couple of months a year — not long enough for the justices to haul their families to town. So the justices all lived, ate and deliberated over cases together under the same roof, in a boarding house. Chief Justice John Marshall insisted on it.

"He wanted to build the bonds between the justices," Fitts explained.

Marshall also insisted on unanimity, Ginsburg said. "Marshall's idea was that [there] should be only one opinion, it would speak for the court. There should be no dissents, and he would write the opinion," Ginsburg said. But, she said, "when the boarding house style of living broke down, so did the unanimity."

These days, unanimity may be elusive on the high court, but food remains a unifying force.

Most of the justices lunch together on days when court is in session — but unlike in Marshall's era, "we don't talk about cases. That's our absolute rule," said Justice Sonia Sotomayor. Instead, there's talk of books, vacations, grandchildren, funny stories — "just the normal type of conversation that people have who want to get to know each other as individuals," she said.

And there are other food rituals designed to promote collegiality among minds finely trained for the art of argument. They bring in snacks to share. Like many an office crowd-pleaser, Sotomayor said she likes to keep a bowl of candy around. Not for herself ( she has Type 1 diabetes) but because people "come to talk to me more when they know there's candy in my office."

The justices toast each other on their birthdays — the chief brings the wine. They sing, too, though "truth be told, most of them can't carry a tune," Ginsburg said.

Ginsburg's late husband, Martin Ginsburg, a brilliant tax law professor and accomplished cook, was known for the cakes he'd bake for everyone's birthdays. He was also a frequent contributor to another court tradition: spouse lunches and gatherings. After his death in 2010, the justices published a cookbook in his memory.

Party planning is also part of the deal — when a new justice joins the court, the most junior justice must throw a welcoming feast. The conservative Justice Samuel Alito threw the liberal Sotomayor's fete — complete with a Spanish guitar player (in honor of her Hispanic heritage) and a bottle of wine with a picture of the Supreme Court and her name printed on the label.

Such "private label" wines could also be considered court tradition. In the court's early days, Chief Justice Marshall, known for his fondness for Madeira, used to bring bottles of it labeled "Supreme Court" to the boarding house for the justices to share — only for "medicinal purposes" or when it was raining. That rule was not so strictly enforced.

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