I think David Brooks gets it right in his column today:
The main axis in McCain’s worldview is not left-right. It’s public service versus narrow self-interest. Throughout his career, he has been drawn to those crusades that enabled him to launch frontal attacks on the concentrated powers of selfishness — whether it was the big money donors who exploited the loose campaign finance system, the earmark specialists in Congress like Alaska’s Don Young and Ted Stevens, the corrupt Pentagon contractors or Jack Abramoff.
When McCain met Sarah Palin last February, he was meeting the rarest of creatures, an American politician who sees the world as he does. Like McCain, Palin does not seem to have an explicit governing philosophy. Her background is socially conservative, but she has not pushed that as governor of Alaska. She seems to find it easier to work with liberal Democrats than the mandarins in her own party.
Instead, she seems to get up in the morning to root out corruption. McCain was meeting a woman who risked her career taking on the corrupt Republican establishment in her own state, who twice defeated the oil companies, who made mortal enemies of the two people McCain has always held up as the carriers of the pork-barrel disease: Young and Stevens.
That seems to be the right explanation for what led McCain to pick Palin. I think Brooks is also on point with his concerns about what a McCain administration will face and what it may need most:
If McCain is elected, he will face conditions tailor-made to foster disorder. He will be leading a divided and philosophically exhausted party. There simply aren’t enough Republican experts left to staff an administration, so he will have to throw together a hodgepodge with independents and Democrats. He will confront Democratic majorities that will be enraged and recriminatory.
On top of these conditions, he will have his own freewheeling qualities: a restless, thrill-seeking personality, a tendency to personalize issues, a tendency to lead life as a string of virtuous crusades.
He really needs someone to impose a policy structure on his moral intuitions. He needs a very senior person who can organize a vast administration and insist that he tame his lone-pilot tendencies and work through the established corridors — the National Security Council, the Domestic Policy Council. He needs a near-equal who can turn his instincts, which are great, into a doctrine that everybody else can predict and understand.
Rob Portman or Bob Gates wouldn’t have been politically exciting, but they are capable of performing those tasks. Palin, for all her gifts, is not. She underlines McCain’s strength without compensating for his weaknesses. The real second fiddle job is still unfilled.
Right diagnosis, wrong cure. What's wrong with having a vice president with the same strengths and weaknesses as the president? It adds predictability in the event of succession. I don't think the vice president should necessarily play the role of "imposing a policy structure." That role should be played by the chief of staff, and someone like Rob Portman in that job is essential to having a McCain White House function well.