The cast of "Survivor" has nothing on Sen. John McCain. Once labeled a vulnerable incumbent, the four-term Arizona Republican is the clear front-runner against challenger J.D. Hayworth after spending some $20 million and casting his GOP opponent as a late-night infomercial huckster in a series of devastating ads. The primary is Tuesday.

As John McCain and J.D. Hayworth have dominated Arizona's political headlines, four Democrats are quietly wrangling for the chance to take on the winner.