It only works once. What if Obama's lackluster performance in the last debate was caused in part by Romney's amazing lie-circus, by his re-invention of himself as a moderate Democrat for election purposes? Why, then Romney's screwed in the other debates. So is Ryan, but for a different reason.
First, Ryan on the chopping block. He's probably been told to stay chilled, to keep his Ayn Rand love to himself, to only talk in broad generalities about everything. But now the game is revealed, Biden ain't gonna let him get away with that. There's just too much of Rand in Ryan's past, too much he's said that he can be held to. If Biden plays this right, and if Ryan wants to be VP enough to stay on-message, Biden will get Ryan to repudiate everything he's ever believed, then nail him by revealing what he's done. But Ryan ain't gonna play that game. He's a true believer. Pushed far enough, he'll stay with Rand and his Right-wing buddies, give up the game, and sell "moderate Romney" down the river. Either way, Biden wins, we win.
Romney is doomed in the next debates. I'm an overly subjective person, so I'll explain why I believe this by recounting an event from a debate tournament in high school. Yeah, I was on the debate team. I was on my way to a win in the tournament when I came across The Guy. We've all faced The Guy, the one who always thinks he can win on charm and low cunning. He smiled at the judge and threw his citation cards on the floor. "He has facts. I have facts. Facts mean nothing." I was so stunned by this, I sputtered and stuttered. "But, but, he can't do that!" was my only response. I lost the debate. He moved onto the finals. The thing is, this only works once and surprise is the key. I was ready the next time. It was a different guy. The second time I kicked his ass. "What my opponent is suggesting is ludicrous in the extreme. We are human, that means we are rational beings. We think, we reason. We base our decisions on insights gained from examining data, study of the past, acquisition of new knowledge, by looking at the evidence. To reject who we are as thinking beings is the height of folly. He would have us abandon three thousand years of rational thought to act like chipmunks."
Obama sees Romney's one-trick pony and comes back at him. That's what I'll be hoping for.