Obama is pretty smart in his put down of Edwards because his attractive appearance is the only thing he brings to the table:

“I want to wait and hear what John Edwards has to say, he’s kind of good-looking,” Obama envisioned Iowa caucus-goers from the small town of Clinton telling themselves. During an appearance in West Burlington, Iowa, the phrase appeared again, this time with Edwards as “kind of cute.”
One Edwards supporter was nonplussed by the reference, coming as Obama stresses rising above petty politics and chafes at press attention to his own good looks.
“Substance is what makes Edwards stand out from the pack,” the supporter said. “Amid the hype, he’s proven time and again to be the candidate with substantive ideas, and that’s what matters most to caucus-goers.”

Though, Obama might not want to focus too much attention on Edwards’ looks because that’s the Democrats’ strategy to win elections. He doesn’t want Edwards to be the Democrats’ stud muffin candidate, does he?