The Connecticut independent, who is backing Republican presidential hopeful John McCain, said Sunday on CBS's "Face the Nation" that "our enemies will test the new president early."

White House spokeswoman Dana Perino said Monday that Lieberman could be prescient.

"I think Senator Lieberman, unfortunately, could be right," Perino said. "And the only reason I say that is because we know that there are people who are very dangerous who are trying to attack us every day."