 Heads of government do this all the time, but Joe Biden does it very infrequently, and it's another opportunity for him to prove that he's nimble on his feet, that he can think on the go and answer all of these questions. If he gets through that, then he's off to a rally in the key state of Michigan on Friday. Come Monday, he's down to Texas, where he's doing a campaign event and another big TV interview. Then it's on to Nevada, talking to black voters and Hispanic voters.