The 2008 presidential race looks to be quite different from all recent contests. Many have noted that this is the first presidential race since 1928 -- 80 years! -- in which neither the incumbent president nor vice president is running.

(Incumbents Harry Truman and Alben Barkley made brief stabs at running in 1952.) But there are two other, more important reasons why this race is different from most other races. One is that the leading candidates are, at this stage, in conflict or in tension with what have been their parties' dominant bases. Two, we have a much better idea of how these candidates would handle crises than we usually do.

Rudolph Giuliani, who runs ahead or at least even in most polls of Republicans, is way off to the left of the party's base. He supports abortion rights and some gay rights measures, and has backed lots of gun-control measures. After his second marriage collapsed, he moved in with a gay couple. Giuliani simply flunks the litmus tests of the cultural conservatives who have had an effective veto on the Republican nomination since 1980.

John McCain, running even or a bit ahead in Republican polls, doesn't flunk most of these litmus tests. But he has been a party maverick, on campaign finance regulation, some tax cuts, climate change and judges. He took some tough shots at conservative religious leaders in 2000, though he's made up for them since.

He's against abortion, but he's never emphasized the issue, and he voted against banning same-sex marriage.

Hillary Rodham Clinton, despite big leads in polls of Democrats, is also in tension with her party's base. She voted for the Iraq war resolution in 2002 and has not, like many other Democrats, apologized for doing so. She has been attacked sharply for her stands on left-wing Websites like Daily Kos. She sometimes sharply criticizes the Bush administration, but avoids the tone of shrill hatred that dominated the party's 2004 campaign and surfaced again in the defeat of Connecticut's Joe Lieberman.

This tension with the party base is surely a liability for Giuliani, McCain and Clinton. But they each, to varying degrees, have an asset that few presidential candidates have ever had: We know how they handle crises or adversity. Going into the 2000 presidential race, few voters felt sure they knew how George W. Bush or Al Gore would respond to crisis. We could only look for clues and make guesses. Continued...