WHEN PRINCIPLE MATTERS. See, man, you try to insert a little nuance into your argument and the young punks jump all over you. But here's the rub -- on issues that are going to be before Congress one way or another, principles don't really matter. Does Joe Lieberman really think the Employee Free Choice Act is important, or is he just pandering to a key liberal interest-group? I don't care. What matters in this instance is that he'll vote for it. It seems that he will, and that's all to the good.
But not every issue has that dynamic. An unprincipled foe of "indecent" pop culture mouths the ritual denunciations when the issue is thrust onto the public agenda. This is unfortunate. The real villains, however, are the people who insist on thrusting the issue into the public agenda in the first place. There are many reasons one might become an agenda-thrusting indecency foe, but principled opposition to indecency is certainly a frequent cause. This gives us, I think, particular reason to worry about principled-but-wrong positions on certain sorts of issues as oppose to unprincipled-but-wrong positions on those topics.
For better or for worse, though, principles tend to matter least on the most significant topics. Therefore, one is generally safe not spending one's energy trying to discern who the principled politicians are and who the unprincipled ones are.