Rove really worked these evangelicals for a long time, there was a huge organisation behind it bringing the Bush message (save the unborn) to local churches, for years. None of the current candidates is going to replicate that level of organisation, though Huckabee will not have to.

Obama looks like he really succeeded in drawing out the youth vote, big, in Iowa. This is a huge selling point. At the same time, the GOP looks to either lose the evangelicals (if McCain or Romney or Giuliani wins), or the patricians (if Huckabee wins). Thompson is the only one who could unite most wings of the party, but he's a singularly uninspiring candidate, he'd be just as bad or worse for the general.

The patricians would line up behind a Bloomberg candidacy, but aside of bringing a lot of money to the table, that's only a 10-15% (rough guess) constituency. Obama likely has most of the right "bipartisan" wing of the Democratic party covered, and Bloomberg is not the right candidate to really organise the 5-10% for whom immigration is a bigger theme than saving the unborn.

The GOP may well try to swiftboat Obama. A Clinton advisor recently claimed they'd bring up the past cocaine use (and had to resign for bringing that up). But it may depend upon the candidate running against Obama.

If it's Giuliani, the attack line is mainly going to be 'Barack Hussein Obama, rhymes with Osama, went to a Madrassa in Indonesia' (cue footage of Bali bombing). Giuliani is just all about total war against Muslims at this point, that's how he's going to fight the general too. Luckily, his chances right now are slim.

I think it's highly likely that they're going to try to pin some sex scandal on Obama, probably related to porn and/or prostitution, possibly actual, possibly in his past, if they go all-out, related to an underage girl -- in a big, big way. The promiscuous black male image is very powerful in the US. That's how they sank Harold Ford's senate run in '06. Still, I don't see them doing this if McCain runs, or Huckabee, because those candidates will get a big dent in their image themselves if they or their surrogates go that sleazily negative. If it's Romney or Thompson, bet on it.

The classical Rovian tactic is to attack an enemy on his strengths, which is why they went after Kerry's Vietnam record in '04 (ripped open a nice old culture war, too). Although the flip-flopping attack line was probably as important. Obama's strengths are his positive outlook, youthfulness, and bipartisanship ('getting things done' 'working together for change'). These are much harder to attack because the media subscribes to them itself on a very deep level.