George Will says it here. I have been thinking it for weeks:

John McCain's best argument for why we should elect him president in 2008 is divided government.

That is, if McCain does not win, prepare yourself for a tsunami of liberal legislation that will make the New Deal and the Great Society look like a day at the beach.

If you believe that government governs best when it governs least, you will want to vote for the contrarian McCain and hope for vetoes.