When Sen. Bob Corker (R – Tenn.) announced he would not be seeking re-election to the U.S. Senate, U.S. House Rep. Marsha Blackburn has been seen as nearly a shoe-in to take his place, due to her experience and name recognition around the state.

However, Corker is clearly not a fan of Blackburn’s.

On CNN’s Sunday edition of State of the Union, Corker told fill-in host Dana Bash he would vote for Blackburn but would not campaign with her against her Democratic opponent, Phil Bredesen.

“I’m supporting the nominee.” Not Blackburn. That’s awkward.

Bredesen is a former governor of Tennessee, as well as former mayor of Nashville. Corker contends in a fairly conservative red state like Tennessee, voters could find Bredesen a more palatable option to a Republican in the age of Donald Trump.

Corker told reporters on Wednesday, “I think he’s got real appeal — I don’t think it, I know it. The question is, in a state like ours that is still a red state, is it enough? I don’t know the answer to that.”

Corker went on to say Bredesen “…was a very good mayor, a very good governor, a very good business person.”

With Bredesen leading Blackburn by 10 percentage points in a poll from Middle Tennessee University this month, Corker’s talking up the Democrat over the Republican could be a harbinger for November.

Losing Corker’s seat would take the Republican’s ability to get very little of their agenda done, to being able to pass nothing at all without Democrats signing on.