Right now conservatism is holding the bag for the most disastrous government in modern history. Four years of a Democratic presidency will give the still-mighty conservative commentariat political ammunition to last another decade or more. A blame-the-White-House electoral strategy could well drive Republican recovery (or gains) in House and Senate seats in 2010 and 2012. Every problem with the economy, Iraq and our role in the world will be portrayed as entirely the Democrats' fault within weeks of the inauguration. Then that much-needed sense of persecution can be stoked to revive the almighty base. (It's difficult to sell angry denunciation when your own guys made the mess, after all.)
Rope-a-dope, basically, and a nice, fully deniable hand-off of the flaming shit the Neocons have created.
(madwriter hits this same theme.)