Appearing on CBS' "Face the Nation" Sunday, the former Democratic presidential hopeful said Clinton must recognize a point at which her White House bid begins to damage her party's general election hopes.

"But I think the one thing that she has to be careful about -- and she doesn't need my advice; she knows this full well -- is she has to be careful about, going forward, is that, if she makes the case for herself, which she's completely entitled to do, she has to be really careful that she's not damaging our prospects, the Democratic Party, and our cause, for the fall," Edwards said.

"If Sen. Clinton doesn't get the nomination, I am absolutely certain that she and (former) President (Bill) Clinton will be out there campaigning for Sen. Obama," Edwards said.