Sometimes politics can be seen as a high-stakes game of chess, a matter of moves and counter-moves, and one that Democrats have lately been weak on.  You couldn’t fault (say) Lyndon B. Johnson for not knowing the moves, but candidates like Dukakis and Kerry seemed to be running for president of the Wonk Club.  As for Hillary, she seemed to figure that when your opponents are mean and clever, you need to be at least mean. 

An article by Jeff Greenfield over at Slate suggest that Obama is playing on a higher level:

In brief: Obama took on a slate of religious leaders, and (by Greenfield’s analysis) sought not so much to win them over, as to tone them down.  And it worked for at least some of them.  As Steve Strang commented,  “He came across as thoughtful and much more of a ‘centrist’ than what I would have expected. He did not appear to be the crazy leftist that is being supported by George Soros and his radical leftist friends.” 

That’s exactly what a Democratic nominee wants the religious right to be thinking.  That’s respectful opposition… which means that those leaders won’t be furiously mobilizing against him.  Others will, of course.  But if he can’t get their vote, it’s just as good to encourage them to stay home and not vote for McCain.

As frustrating as it must be for progressives, this is still a very religious country, and a successful presidential candidate has to at least appear to be a strong Christian.  Kerry appeared to be uncomfortable discussing religion (despite his nominal Catholicism); Obama is not.