Presidents and First Ladies Trivia

[Eva Elisabeth]

Referring to his 1976 electoral campaign, Jimmy Carter remarked:

"I was broke, I had lost some primaries, I didn't know where I was going to go next, and the fact that ...and... were willing to help me kind of turned the tide."

Who turned the tide? (I'm just seeking the more famous one of the two missing names, but giving the other would be too much a hint!)