4) Ryan is from a battleground state, Wisconsin, and a battleground region, the upper Great Lakes.

5) Ryan’s youth, vigor, likability and Jimmy Stewart persona — well, a wonky version of George Bailey — would be an immediate shorthand signal to voters that he’s a different kind of Republican. He also has a compelling life story to tell.

6) Obama suddenly and unexpectedly to Washington insiders looks beatable — by the right candidate.