In a mere 90 minutes, Biden managed to throw Hillary Clinton under the bus, CIA Director David Petraeus under the bus, our Afghan allies and the Afghan people under the bus and our Middle Eastern allies who fear an Iranian bomb under the bus. Which means that Obama, in trying to explain himself, is in for a bumpy ride. There is a reason Biden is generally kept out of press earshot. He is forever poised between an indiscretion and a different indiscretion.

But Biden’s performance will be forever remembered not for its content but for its tone. I have occasionally admired Biden’s emotional transparency and “happy warrior” enthusiasm. His debate presentation in Kentucky, in contrast, was a collection of disturbing, disorderly appetites. He displayed scene-chewing antics and preening exhibitionism and smirking rudeness and egotistical exuberance and bullying condescension. It was the attack of the feral ham actor. It would have been embarrassing if done in front of a mirror, much less on a debate stage.

This has complicated Obama’s life in another way. The road-rage wing of the Democratic Party (the GOP has one as well) views the Biden meltdown as a pioneering achievement in political discourse. Former governor Howard Dean — an expert in nontraditional political deportment — argues that Biden is “an excellent role model” for Obama. Since adopting this model would disqualify Obama for the presidency, elements of the left are bound to be disappointed with the president’s debate performances. And it will be harder for Obama to claim the mantle of bipartisanship when his running mate is celebrated for his incivility.