Yglesias is discussing some interesting poll data about the political attitudes of the public on specific issues. Unfortunately, it's some pretty horrible discussion. I'll leave alone that he thinks "Democrats could reap some major gains by taking a more conciliatory stance toward traditionalist sentiment in America", and yet all Democratic candidates have been Christian while it's pundits like him who call Catholicism "a false gospel."
He focuses on issues Democrats could give up ground on (Ten Commandments displays, school prayer), and ones that they don't need to (abortion). Yes, those Democrats really should stop voting for so many bills that ban the ten commandments, school prayer, and let that Schiavo woman die. Oh wait, there's no legislation about this at all (or when there is, Dems vote for it). All the contentious issues in our "culture war" are decided by judges. Democrats have no power here. I mean, suppose you were Harry Reid, and decided "Hey, we can definitely win the next Presidential election if the Ten Commandments go up over the Supreme Court building." What would you do to could accomplish this?
(I suppose Democrats could look for less separationist judges, but the idea that the school prayer in public schools violates separation of church and state is so direct and so enmeshed in precedent, that you'd have to nominate judges so extreme that you lose a lot of stuff first.)
Democrats could go make empty campaign speeches about returning religion to America even though they know they have no power to actually enact that. A lot of speeches, enough to convince people they'd care. Or push for a Constitutional amendment for school prayer. I dunno. I don't think such extreme measures really would be possible with the base. They might accept compromise for practical concessions... but not the idea of trumpetting around empty speeches for the sole reason that these are against their principles.
Again, bad effects of our inability to really change these laws and allowing one party to campaign on the basis of promises they never msut be expected to keep.
(To be honest, Kerry campaigned for universal healthcare, a plan that with this Congress would be just as unlikely to be fulfilled.)