President Obama is clearly the biggest star not invited to Chelsea Clinton's wedding this weekend, but protocol experts say the bride's mother, Secretary of State Hillary Clinton, was under no obligation to invite her boss.
These days, the rule of thumb at any wedding -- no matter how high-profile -- is that the bride and groom, not their parents, have final say on the guest list. Since Obama does not have any longstanding personal relationship with the former first daughter, he doesn't exactly qualify as family and friends.
"It's their special day," Pamela Eyring, president of The Protocol School of Washington, said about Chelsea Clinton and groom Marc Mezvinsky.
There is precedent for a sitting president to be invited to a Cabinet member's wedding soiree, but it goes back a few years -- Abraham Lincoln attended the wedding of Kate Chase Sprague, the daughter of his Treasury Secretary, Salmon P. Chase, in 1863. President George H.W. Bush also attended the wedding of two White House staffers in 1990.
But a wedding that involves the daughter of a former president and a current Cabinet member is a unique situation. Eyring said the bride and groom already have to deal with the extra security and attention surrounding former President Clinton. To invite the Obamas on top of that could "upstage" the ceremony itself, she said, and turn the affair into a logistical maze.
"I would think it's probably to keep the chaos in control and to keep the balance of the event," she said. "They have enough competition with their own parents."
Administration weddings don't necessarily involve administration guests. Donald Ensenat, who served as U.S. chief of protocol during the Bush administration dealing mostly with diplomatic issues for the State Department, said he attended Jenna Bush's wedding after he left office, but that it was "strictly" family and friends.
"That's totally a domestic, private matter. ... They can invite whoever the hell she wants," he said of the Clinton wedding. "There's no official guidance."
Details have trickled out about the guest list at the wedding, which will take place Saturday at an estate along the Hudson River in New York.
The Hudson Valley News has reported a juicy lineup of celebrities who may attend, including Barbara Streisand, Ted Turner and former Democratic Party Chairman Terry McAuliffe. The New York Daily News, meanwhile, reported that former Vice President Al Gore will not attend.
No reports have surfaced that any Obama administration members were invited.
The president himself did not appear to feel snubbed when asked about his non-invite during his pre-taped appearance on ABC's "The View" on Thursday.
"I was not invited to the wedding because I think Hillary and Bill, properly, want to keep this thing for Chelsea and her soon-to-be husband," Obama said. He added that the bride and groom would not want two presidents at the same wedding.
"All the Secret Service ... all the gifts being torn apart," he said.
Cynthia Lett, protocol expert and director of the Lett Group, said the Clinton wedding is "very unique." She said even though it would seem reasonable for the secretary of state to invite her boss, it's really up to Chelsea.
"It's not according to the mother of the bride. It's according to the bride," she said.
"So the bride has to say, 'I want him there.' This is not a state affair."