"Young White House aides frequently mocked Biden’s gaffes and lack of discipline in comparison to the almost clerical Obama."

"They would chortle at how Biden, like an elderly uncle at Thanksgiving, would launch into extended monologues that everyone had heard before....  Obama and [Hillary] Clinton both viewed themselves as pioneers who worked their way through America’s elite colleges. Obama went to Columbia University and Harvard Law School, where he headed the law review; Clinton went from Wellesley to Yale Law School. They shared a work style as well, always sure to do their homework and arrive at a meeting prepared to get to the crux of an issue. 'They do the reading,' said one former Clinton aide. 'In Situation Room meetings, she had the thickest binder and had read it three times.' Biden’s own academic career was unimpressive—he repeated the third grade, earned all Cs and Ds in his first three semesters at the University of Delaware except for As in P.E., a B in 'Great English Writers' and an F in ROTC, and graduated 76th in his Syracuse Law School class of [1968].... He was not a binder person, Clinton and Obama aides said.... Biden’s tendency to blurt out whatever was on his mind rankled Obama, who wasn’t afraid to needle him for it. In his first press conference in 2009, the young president quipped 'I don’t remember exactly what Joe was referring to—not surprisingly'.... Biden has long been defensive about suggestions of being dumb or a lightweight—a narrative that took hold during in his first campaign for the presidency, in 1988...."

From "'The President Was Not Encouraging': What Obama Really Thought About Biden/Behind the friendship was a more complicated relationship, which now drives the former vice president to prove his partner wrong" by Alex Thompson (at Politico). Lots more at the link.