John McCain finally announced that he is running in 2008 (as if we didn't know already). McCain has come a long way from 2000 when for a moment it looked like he might win the nomination, though machinations of Karl Rove prevailed in the end. Back then he was a bit of maverick and much liked by independents and Democrats. In fact, many independents and Democrats showed up in Republican primaries and handed McCain a few key wins. If Bush the team did not resort to dirty smear tactics against him, he might even have staged a surprise victory.
But in the past seven years McCain lost many of the advantages he had at that time. For one thing he realized that he needs the support of religious right and this made him do some pretty crazy things like showing up at Jerry Falwell's Liberty University. He has gone back some liberal things he said about gay marriages. In his attempt to win favor in Iowa, he also disowned some courageous things he said about ethanol subsidies (in 2000 he skipped the Iowa primary). All this destroyed the "straight-talking" image that was his pride some time ago. There are also questions about his age. He is doing his best to counter these (showing up at Letterman to announce his candidacy).
McCain has a curious problem: he has a good chance of winning a general election, but great trouble winning Republican primaries. He did not win a single primary in 2000 where voting was restricted to Republicans. Much of the last six years he spent addressing this problem. But in the process he lost many independents and Democrats. And it remains to be seen if he has done enough to win the hearts of the Republicans.
Right now he comfortably trails Giuliani, though it is too early to say anything. Most likely he will not need to contend with dirty Rove-like tactics, but drawing Republicans away from the 9/11 hero Giuliani will be a challenge. It must be said also that McCain has a far more extensive national presence which will surely give him an edge over Giuliani.