There he goes again, and again

This is one of the oddest arguments I've seen this political season:

Please. Biden's blunder couldn't matter less. Not because gaffes never matter—they can, if they play into public perceptions of the candidate's character—but because Joe Biden is gaffe-proof. Whatever traps he sets for himself, however many minorities he offends, he always seems to wriggle out. It's almost as if, by committing so many gaffes, he has become immune to their effects. "Joe Biden Makes Gaffe" is the new "Dog Bites Man."

You make a gaffe, and it could end your political career. But if you're a walking gaffe machine, you get a pass, and the more mistakes you make, the better off you actually are. It's the "There he goes again" defense