“I don't know where it comes from,” Mrs. Edwards told Time magazine. “I don't begin to understand it. But you can't pretend it doesn't exist, and it will energize the Republican base."

Former Sen. John Edwards, D-N.C., trails Clinton and U.S. Sen. Barack Obama, D-Ill., in the polls. His wife has been playing a major role in the campaign, drawing media attention with her attacks on right-wing firebrand Ann Coulter and criticizing Obama and Clinton.

"Their nominee won't energize them, Bush won't, but Hillary as the nominee will,” Elizabeth Edwards said. “It's hard for John to talk about, but it's the reality."

In her interview with Time, Mrs. Edwards also echoed earlier comments that her husband was not getting as much attention because he is competing against the first woman and first black presidential candidates thought to have a good chance of nomination and election.