McCain's speech tonight.
Strategically, he could take a page from the Reagan playbook and tell the people "they talk about change, I am the real change." History repeats itself, both in how "change" is one party's appeal, and that move by Reagan destroyed Jimmy Carter's chances of re-election.
This time around, McCain can outright steal Obama's only message using the same tactic. Palin's performance last night makes it a believable argument at this point. She is "none of the above" that would win a lot of polls if that option were given. She is change, both for the party and for Washington since she's an outsider. It would also undercut the "McBush" PR stunt the Democrats are trying to pull against him.
The technically correct approach for his speech tonight is to go through a laundry list of issues and solutions he proposes, much as Obama did. The problem with that is, you get the "fact checkers" in the media telling everyone how massive Obama's spending programs are or how big a debt McCain would run up. And the candidates as presidents rarely have the actual power to get much of their agendas passed.
If he made a "bet" on Palin, now is the time to double down on that bet. The strategy should be to maximize the expected bounce every candidate gets coming out of their conventions.
What you won't see is him attacking Obama too much - that was left to the rest of the speakers at the convention. His need is to seal the deal with as many people as he can while he's got the biggest megaphone in the world.
On a side note, Larry King Live was dedicated to Republican response to the Democrats' convention last week, this week it's the reverse. It was interesting to see what the war room's rapid response was to Palin's speech. They clearly are having trouble figuring out what to do. Half of them took the approach of deflecting from her performance - "the election is still about the men at the top!" while the other half continued the talking points from before the speech.
Finally, her speech was seen by 30M people. Obama's speech at the football stadium was seen by 39M.