The former president and once-again-future president, who are historically something less than besties, chatted it up before the service began. (Michelle Obama was not in attendance.)

Donald Trump shook hands with Mike Pence at Jimmy Carter's state funeral -- a notable exchange as the two men have not interacted publicly in years.

Trump is obviously no fan of Biden, but Obama and his veep also have a famously complex relationship, only made more so after Obama helped nudge Biden to quit the presidential race last summer. Surely Obama feels some frustration that Biden fumbled a possibly winnable race; maybe he couldn’t help spill to his sworn enemy?