Washington University has had a tremendous run of luck landing political debates. It played host in '92, '00, '04, and is welcoming Governor Palin and Senator Biden here tonight. It'd be great if some sleuthing undergrad managed to figure out how.

Both camps have been trying to tramp down expectations, and the media, for its part, has stressed that vice presidential debates -- as compared to those between ticket headliners -- have historically been far less important.

But there's a good chance that this will be the most significant vice presidential debate we see in our lifetime.

And, if it weren't for playoff baseball, I think tonight's event would make a run at beating out last Friday's 52.5 million viewers. With 50 million people voting early, it's also worth noting that this could be the last formative impression that a number of voters have of each camp.

Joe Biden will be well served to sit back. Polls are moving in the Dems' favor, and Obama appears to have convinced voters that he has a better command of the economic challenges facing the country. But it'll be difficult for Biden to coast as he should. It'll be hard for him to sit back and listen to Palin stumble and generalize on issues of foreign policy. I can almost hear him already, "Governor Palin, do you even know who the President of ______ is? Governor Palin, I was there when..."

For anyone who hasn't seen the worn out clip of George Bush Sr. and Representative Geraldine Ferraro, you can find it here.

My perception of Sarah Palin -- from her limited interviews and from past debate footage -- is that she's impressively disciplined. She's content to step back from issues she doesn't command, and speak to them in general, principled terms. I think it's likely that American voters -- despite the lessons from GWB -- remain willing to vote for someone whose moral compass seems to align with their own, even if their command of issues isn't stellar.

Most Americans can't name the leader of North Korea or discuss the intricacies of Iranian politics. And, to some extent, they bristle at those who can. There's a core of voters in this country that cling to candidates they think -- upon reviewing all information -- might reach the same moral verdict that they would. If Sarah Palin can capture that sentiment and draw Biden out just once, this could go in her favor.

More from the Spin room later where Joe Lieberman, Lindsey Graham, Fred Thompson and Mayor Rudy Giuliani will be pushing Palin. Democrats have yet to announce who will be backing Biden.

--Brian Till