And it's Joe Biden

Barack Obama has chosen Joe Biden to be his running mate. (BBC News: Obama picks Biden as running-mate ) It's a bold move in one sense - Delaware has just three votes in the electoral college and is a pretty reliable blue state. But in another it means Obama now has his own Lloyd Bentsen who could prove to be far more credible than the Presidential nominee. And a campaign promoting "Change we can believe in" now has not only an all Beltway ticket but now includes a man who entered the Senate when Obama was prepubescent.

If there is one significant move in all this it's that increasingly the Vice Presidency is tacking away from being a stepping stone to the Presidency - who can seriously envisage a Biden 2016 bid? Instead the role is becoming more and more a significant office in its own right. And in turn that will make nomination battles more open and competitive. Dick Cheney (who also comes from a tiny state his party never needed to worry about) may well have made his best long term contribution to the office here.