His column on why Obama’s situation isn’t analogous to Reagan’s scores some good points:

The comparison to Reagan may give Obama cheer, but it is not really apt. For even in Reagan’s darkest days when, according to Gallup, six out of 10 Americans reported that they did not like the job he was doing, an astounding six in 10 nevertheless said they liked the man himself. He was, of course, phenomenally charming, authentic and schooled at countless soundstages in appearing that way. Just as important, the public had faith in the consistency of his principles, agree or not. This was the Reagan Paradox and it helped lift his presidency.
No one is accusing Obama of being likable. He is not unlikable, but he lacks Reagan’s (or Bill Clinton’s) warmth. What’s more, his career has been brief. He led no movement, was spokesman for no ideology and campaigned like a Nike sneaker — change instead of swoosh. He seems distant. No Irish jokes from him. For the average voter, he casts no shadow.
Reagan, by contrast, had been around forever. He was not defined solely by gauzy campaign ads but by countless speeches, two contentious and highly controversial terms as California governor, and a previous race for the presidency. There was never a question about who Reagan was and what he stood for. Not so Obama. About all he shares with Reagan at this point are low ratings.
What has come to be called the Obama Paradox is not a paradox at all. Voters lack faith in him making the right economic decisions because, as far as they’re concerned, he hasn’t. He went for health-care reform, not jobs. He supported the public option, then he didn’t. He’s been cold to Israel’s Binyamin Netanyahu and then all over him like a cheap suit. Americans know Obama is smart. But we still don’t know him. Before Americans can give him credit for what he’s done, they have to know who he is. We’re waiting.

In short, no one who voted for Reagan said a year and a half later, “Who is this guy?” And comparatively few people who voted for Reagan said, “This isn’t what I voted for.” Obama’s being defined by the times and actions in a way that Reagan wasn’t because Obama campaigned as a brand-name messiah (Now packed with more Hope! And twice they daily allowance of Change!).