Is Barack Obama hot because of who he is, or who he is not? I suspect the latter. He isn't Hillary Clinton.

Hillary's the frontrunner and this happens to frontrunners.

I think it must be frontrunner angst.

It's like buying a car. You're all set on a model, then you see another model and you wonder: Maybe I should have that model?

A lot of Democrats are wondering if they can do better than Hillary.

That maybe Hillary's good, but this Barack guy is better? Maybe stands a better chance of winning?

If I've seen it once, I've seen it at least a few times.

George Bush was a frontrunner for his party's nomination in 2000, until the party flirted with John McCain. And then it didn't.

Just like Jimmy Carter emerged the frontrunner in 1976 after shocking folks in Iowa, until the party started flirting with then California governor Jerry Brown. And then it didn't.

Frontrunners who are frontrunners early have to deal with this: peaking too soon, raising questions too soon, raising doubts too soon.

That's not to say Hillary can't still be who she is. It just confirms Barack can still be a rock star precisely because of who he is not.

Watch Neil Cavuto weekdays at 4 p.m. ET on "Your World with Cavuto" and send your comments to cavuto@foxnews.com

Neil Cavuto serves as senior vice president, anchor and managing editor for both FOX News Channel (FNC) and FOX Business Network (FBN). He is anchor of FNC's Your World with Cavuto - the number one rated cable news program for the 4 p.m. timeslot - as well as the FNC Saturday show Cavuto on Business. He also hosts Cavuto on FBN weeknights at 8 p.m. In addition to anchoring daily programs and breaking news specials on FNC and FBN, Cavuto oversees business news content for both networks and FNC's weekend business shows, including Bulls & Bears, Forbes on Fox, and Cashin' In. Click here for more on Neil Cavuto.