Why isn't McCain a "proud conservative" anymore?

After the last week's debate, I noted that McCain had kicked his old habit of calling himself a conservative:

McCain never presented the conservative alternative to Obama. He never even called himself a conservative last night. He was wandering all over that red carpet, microphone in hand, and I have the feeling, in retrospect, that he was truly bewildered, mouthing old phrases, trying to slip by. But one old phrase that was missing was "I'm a proud conservative." Remember when he used to say that?... McCain has lost definition. He's stumbling along to the finish line, hoping to achieve his lifelong ambition, to seize the crown at last. But why? To show he can get along with Democrats? I worry about what awful innovations the new President will concoct in league with the Democratic Congress, but at this point, I'm more worried about McCain than Obama.

Now, I'm checking the transcript from last night. The word "conservative" appears exactly once.. It's said by McCain, but he's quoting Obama:

... I believe strongly that we should have nominees to the United States Supreme Court based on their qualifications rather than any litmus test. Now, let me say that there was a time a few years ago when the United States Senate was about to blow up. Republicans wanted to have just a majority vote to confirm a judge and the Democrats were blocking in an unprecedented fashion.

We got together seven Republicans, seven Democrats. You were offered a chance to join. You chose not to because you were afraid of the appointment of, quote, "conservative judges."

That is, Obama, in McCain's view, was using a misnomer, denoting highly qualified jurists with a political term.

Why isn't McCain a "proud conservative" anymore? Last week, he mentioned Ronald Reagan 3 (but only to opposed him or liked the way he worked with the liberal Speaker of the House). This week, he never mentioned him once.

Is there some sort of idea that if you think McCain is too liberal, you still have to vote for him, because if he's too liberal, then Obama is really too liberal? I don't buy that. Better a principled, coherent liberal whose liberal choices will, if they don't go well, be blamed on liberals than an erratic, incoherent liberal whose liberal choices will be blamed on the party that ought to get its conservative act together.