McCain would play well in AZ (home state) and VA (strong NatSec Community). If he brings over deficit-minded suburbanites and National Security Conservatives, its game over. Marginal improvements in OH, IA, and NM also put Kerry over the top.
Not to mention, it's two Vietnam War heroes vs Dubya with his iffy military record.
The messes of Bush's second term would be Kerry's problem. I don't think he'd get much done, but the plus side is that you'd have an experienced foreign policy two years sooner than OTL (when it took Dubya until late 2006 to get a firm grip on the situation).
The 2004 Senate elections will probably go better for the Democrats. Alaska, Florida, Kentucky, and South Dakota go Democrat. Louisiana probably goes to a runoff, and considering Vitter (the only Republican) only got 51% OTL whereas the four Democratic Senate candidates got 48% OTL, I'd put that as a toss-up.
I wonder how the 2005 Arizona Senate Special Election would go.
The 2006 elections will go very differently. No Democratic wave means the Republicans hold Missouri, Montana, Virginia, and Rhode Island.
Ohio is a toss-up. Pennyslvania will still go red because conservatives were pissed at Santorum for supporting Arlen Specter in 2004.
Michael Steele could potentially pull an upset in Maryland. New Jersey might be a toss-up, as even in a very blue year it was only 53.4-44.3.
2008 will be a wave year for the GOP when the economy goes kaput.
Alaska, Louisiana, Minnesota, New Hampshire, North Carolina, and Oregon definitely go Republican.
Dick Zimmer in New Jersey may or may not win. NJ is a weird state and in a red wave year the socially liberal Zimmer could maaaaybe take the seat.
If the GOP could convince Johnson to run for Senate in 2008, he could maybe hold the seat in New Mexico. But until 2018 and the prospect of being an independent swing-vote, he hated the idea of running for Senate.
These two are definitely long shots though.
As for the 2008 nominees, it could be Romney. I also think that George Allen clinching the nomination given that he wouldn't lose reelection TTL.
If Kerry and Romney are nominees, I swear upon the constitution and apple pie and everything American that there better be some third-party candidate saying that This country deserves better than two rich jerks from Massachusetts.
Maybe Ron Paul runs in 2008, but if he didn't run OTL why would he here?
If Bush here loses the EC but wins the PV, could he come back in 2008?