If Barack Obama has a bit too much restraint about his persona for the commentariat, Joe Biden is the White House's exuberant and impassioned id. From "This is a big fucking deal!" to remarks that fall in Onion territory, the tactile, voluble vice president has stepped forward at key moments in White House history to say what everyone is thinking (and also, sometimes, to step in it).
Today's example was Biden unleashing a stream of wholly warranted invective at the Boston Marathon bombers. Speaking at memorial services for slain M.I.T. police officer Sean Collier, he called bombers Dzhokhar and Tamerlan Tsarnaev "two twisted, perverted, cowardly knock-off jihadis."