It most definitely was not tongue in cheek.
She said she wished he was running against Lincoln Chafee and that way she could be happy for him to beat a Republican even though he was in the 'wrong party.'
She said she wished he would switch parties because she just liked him so much.
Then I guess she realized what she was doing and she said, "I guess I should really stop talking about how much I like Harold until after the election, and people in TN, you should not vote for Harold, you should vote Republican. I just wish he was running against a republican I want to lose."
That is not an exact quote, but, it's real close to what she said. There may be a transcript at Fox, I don't know.