A leftover from last night that shouldn’t go unremarked upon. If it seems weird to you that Biden, the sitting VP and a guy who began serving in the Senate when Barack Obama was all of 11 years old, would need The One’s “blessing” to make a run at the big prize, it … seems weird to me too. But there was a chance, I guess, that O, as the head of the party, would tell Biden that Hillary’s their best bet at the nomination and that he’d push strenuously behind the scenes for Democratic donors and operatives to unite behind her if Biden jumped in. He couldn’t stop Biden from running, but he could make it so difficult for him that it wouldn’t be worth doing.

Obama, very interestingly, apparently gave no indication that he’d stand in Biden’s way. The question is why.

Vice President Joe Biden received President Barack Obama’s “blessing” to make a 2016 bid for the White House, according to a senior Democrat…

The Vice President was expected to huddle at his home Monday night with Anita Dunn and Bob Bauer, the husband-and-wife team who have been at Obama’s side for much of the last decade, two people familiar with the meeting told CNN. Steve Ricchetti, the Vice President’s chief of staff, was also expected to attend…

Dunn and Bauer would be a high-profile addition to any potential campaign, and could send a signal to other Democrats that they should join Biden’s effort. It is not known if they would ultimately work for Biden if he does enter the race.

Again, the question is why. The most innocuous explanation is pure personal affection. Biden’s a bereaved dad and he’s been a loyal soldier for Obama. This is his last shot to run for president. No matter how many misgivings Obama and his team have about candidate Joe, O owed it to him as a friend not to interfere with his candidacy. It’s no reflection on Hillary, just kindness at work. Another explanation is that the Biden/Warren rumors are true and Obama sees that as a better bet for the future of the party than Hillary/Whoever. Warren would steer the party towards the type of liberalism that Obama sympathizes with; Biden, as I argued yesterday, would be a bridge from his administration to hers. Biden would also be a more loyal keeper of Obama’s legacy than Hillary would be, since she’s already tied to another Democratic president. If O’s worried about a Dem successor undoing some of his policies, especially his foreign policy, he’s better off with the faithful administration soldier than with Clinton.

Of course, there’s another possibility. The WSJ:

The President is enough of a cold-blooded politician to know that a considerable part of his legacy will depend on whether a Democrat succeeds him in the Oval Office. Above personal feelings, he wants a Democratic nominee who can win in 2016.

Mr. Biden ran for President in 1988 and 2008 and lost, so why would he be a better candidate now? The Veep would be starting late, and most Democratic officeholders and donors are already committed to Hillary and Bill. Mr. Biden might figure he can run as a more authentic tribune of the middle class, but Bernie Sanders has a head start running as the economic populist. On paper at least, Mr. Biden would still be a long shot to defeat the Clinton machine.

Which leads us to wonder what Mr. Biden and Mr. Obama know about Mrs. Clinton’s mishandling of classified information on her personal email server while running the State Department. The FBI is now investigating, and it’s hard to believe the White House wouldn’t have some inkling about the seriousness of that probe.

Even if you think the FBI wouldn’t tip the White House to its findings, it may be that one of Hillary’s own insiders has some idea of what’s on the server and has tipped Obama to it. I remember reading after the 2008 primaries that members of John Edwards’s staff had somehow figured out what was going on with Rielle Hunter while the campaign was in full swing, creating a conundrum for them. Should they keep quiet out of loyalty to their candidate, knowing that leaking the info would destroy his campaign? Or should they speak up out of loyalty to their party, knowing that if he won the nomination and the scandal came out later, it might destroy Democrats’ chances to win the presidency? There may be someone in Hillary’s orbit who’s struggled with that same dilemma and opted for loyalty to the party, whispering to party elders that Emailgate’s going to get worse and that they’d better get cracking on a presidential plan B. (Then again, aren’t Hillary insiders known for their fanatic loyalty and excruciating sycophancy? Who would dare betray Herself by trying to entice Biden into the race?) Or maybe we’re overthinking this: Maybe no one’s leaked anything to the White House about what Hillary’s server contains and Obama’s simply acting upon his own judgment here. “Is it likely,” he’d ask himself, “that Hillary Clinton is a corrupt imbecile who’d put state secrets at risk for no better reason than to keep her e-mail correspondence away from the prying eyes of State Department archivists?” That question answers itself. Enter Biden.