Eventually, analysts say, the battle will boil down to two highly organized, well-funded efforts that will succeed or fail based on how the candidates themselves persuade voters on the usual factors – electability, issues, experience, and character.
"In politics as in romance, passion doesn't last forever," says Jack Pitney, a political scientist at Claremont-McKenna College in Claremont, Calif. "[Obama] has to manage what all presidential candidates have to manage, and that's the balance between inspiration and substance."
Passion for both candidates
To be sure, Clinton's supporters can get just as passionate about her as Obama's do about him. William Klein, a Democratic publicist from Silver Spring, Md., says he's excited about Clinton both because of her experience and because she's a woman. He likes the fact that his 11-year-old daughter is excited about the idea of having a woman president.