Conservative talker Glenn Beck declined to endorse J.D. Hayworth (R) during an interview with Don Imus on Fox Business Network Wednesday morning.

Beck said he was for Sen. John McCain (R-Ariz.) going "off into the sunset."

Imus expressed disbelief. He asked Beck if he's for "that fat, undisciplined maggot … shock jock?"

Beck refused to say he's backing Hayworth, the senator's primary opponent. "Just because I'm for John McCain going away now, doesn't mean I'm for J.D. Hayworth," he said.

The McCain camp pointed out that Beck was the latest in a long line of prominent conservatives who have declined to endorse Hayworth, but this snub is likely to hurt more.

Officials with the Hayworth camp told The Ballot Box in March they were hoping to have Beck's endorsement.

Hayworth and Beck overlapped as broadcasters in the Phoenix market and Hayworth's campaign anticipated that personal connection would translate into an endorsement.

Watch the full clip below:

Updated at 4:42 p.m.