No question Palin helped herself tonight, but that's only because she had so far to climb. If you're grading on anything other than a massive curve, Biden wins hands down.

The beauty of Biden is that he can go blow for blow with Palin on ordinary Joe-ness, then actually know what he's talking about when he answers questions. Palin talks about the mean streets of Wasilla, Biden talks about the mean streets of Scranton. Palin talks about her son in Iraq, Biden talks about his son in Iraq. Palin talks about being the mother of a child with special needs, Biden talks about being a widower with two badly injured boys. Every time you thought she might claim an emotional advantage, Biden evened the emotional score.

But, man, ask the woman to grapple with a substantive question and you worry she's going to hurt herself. My favorite Palin response of the night:

IFILL: What has this administration done right or wrong -- this is the great, lingering, unresolved issue, the Israeli-Palestinian conflict -- what have they done? And is a two-state solution the solution?

PALIN: A two-state solution is the solution. And Secretary Rice, having recently met with leaders on one side or the other there, also, still in these waning days of the Bush administration, trying to forge that peace, and that needs to be done, and that will be top of an agenda item, also, under a McCain-Palin administration.

Israel is our strongest and best ally in the Middle East. We have got to assure them that we will never allow a second Holocaust, despite, again, warnings from Iran and any other country that would seek to destroy Israel, that that is what they would like to see.

We will support Israel. A two-state solution, building our embassy, also, in Jerusalem, those things that we look forward to being able to accomplish, with this peace-seeking nation, and they have a track record of being able to forge these peace agreements.

They succeeded with Jordan. They succeeded with Egypt. I'm sure that we're going to see more success there, also.

It's got to be a commitment of the United States of America, though. And I can promise you, in a McCain-Palin administration, that commitment is there to work with our friends in Israel.

Right: Forge that peace, no second Holocaust, two-state solution, capital in Jerusalem. It's like she's just randomly spewing every talking point she's ever uploaded on Israel. (Which I'm guessing is what happened.) 

Biden by contrast, hit the same question out of the park: The Bush administration legitimized Hamas by holding an election in the West Bank, then let Hezbollah fill the vacuum in Southern Lebanon by not using NATO troops. Checkmate.  

I also thought Biden was brilliant at poking through Palin's tax blather, which was more or less the only thing she had to say about economics:

Look, all you have to do is go down Union Street with me in Wilmington or go to Katie's Restaurant or walk into Home Depot with me where I spend a lot of time and you ask anybody in there whether or not the economic and foreign policy of this administration has made them better off in the last eight years. And then ask them whether there's a single major initiative that John McCain differs with the president on. On taxes, on Iraq, on Afghanistan, on the whole question of how to help education, on the dealing with health care.

Just terrific stuff. It's a simple choice: Change versus more of the same. Everything else is noise.

My completely impressionistic take on Palin's performance tonight is that it mirrorred her campaign performance so far (if not quite as dramatically): When Palin started off, you thought, "Wow, she seems so fresh--so human and easy to relate to. How can we compete with that?" Then, as the debate wore on, you thought, "Hmm, okay, she still seems human, but not quite what I'm looking for in a vice president." And, by the end, as the vacuous answers piled up, it was more like, "Good God, keep this woman away from the Oval Office." Which is the story of the last month, too.

Palin just isn't a candidate who wears well over any extended period of time, whether it's a 90-minute debate or a 60-day campaign. The reason is that she only has one mode: human and relateable. That's fine when the topic is middle-class pain. But there are whole classes of issues--foreign policy chief among them--where human and relateable aren't what you're looking for, even if you're an uninformed voter. 

--Noam Scheiber