Former President Bill Clinton told ABC's Bianna Golodgrya that President Barack Obama fight back against "birthers" who questioned his citizenship.

"If I were them, I'd be really careful riding that birther horse too much," Clinton said of potential Republican presidential candidates. "Everyone knows it's ludicrous."

"I think one of the elementary rules of combat is you don't want to get in your opponent's way if he's shooting himself in the foot," he added.

This video is from ABC's Good Morning America, broadcast April 4, 2011.