I don't understand what Ryan's thinking. Willard's chances were slim before he accepted, and when veep candidates lose (Lieberman, Palin, Kemp, Quayle, Ferraro), they are generally mothballed.
Now Ryan certainly won't get blamed for the loss -- just as Palin wasn't. But he'll have the stink of a loser on him, and I suspect, is going to have a rocky campaign, which will scuff him up a bit.
On the other hand, if he had waited it out, he could've been the nominee in 2016.
Don't get it.