I have to say, I thought choosing Palin was absurd at first, but I've come to see it as an inspired stroke of genius.

Forget about what the candidates actually do and who they actually are for the moment (the truth is they are probably much more similar than different on 95% of the "issues"). But let's set this aside and look at it from the drama of the election.

By choosing Palin, McCain seeks to take away the "change" message from Obama. As a first-term Senator, Obama doesn't have much of a record yet, so being a "change" candidate and "outsider" and a "historical candidate" is pretty much all he's got to run on. That and some good oratory skills. John Kerry had the whole country saying "anyone but W" and he lost. The "we're not Republicans" platform will only get 45% of the vote. So the change message is vital.

Seen that way, this is very much like the Kennedy / Nixon race of 1960. Establishment vs. new blood.

So McCain tries to blunt that strategy by picking (whatever else she may be) a charismatic Washington outsider and a historic candidate of his own. The subtle point is that it doesn't need to be 100% effective. All they need to do is establish parity on the "change issue", and McCain will win because he's the father figure. Americans traditionally love a tough-talking, hard-ass father figure for a president, especially in times of "war".

Seen purely as a strategic move, I think it's high risk, but potentially election winning for McCain.