Paul at Powerline ponders the "curse" of Senator John McCain's quest for the Presidency: 

The most common explanation for this phenomenon is that Senators are called upon to make tough votes that tend to undermine their popularity. Though this probably is an important factor, let me suggest another -- the Senate is a fairly rotten place. For example, it's the kind of place where 14 Senators can hijack the judicial confirmation process. Worse, it's kind of place where a handful of Senators can reach a deal on fundamental issues about the identity of America and then try to force a vote on the resulting 600 page bill with little time for the body as a whole to study or debate it.

This year, John McCain is the lone first-tier Republican presidential candidate jeopardized by the "curse of the Senate." But don't think of McCain as a potential victim of the curse; think of him as the embodiment of the sort of high-handedness and arrogance that lies behind the curse.

Curse of the Senate?  Nah.  He has always reminded me of John Murtha.  A volitile "bull in a china shop."  A hero, nonetheless -- McCain is a victim of his own undoings.

For the sake of what is left of your image, Senator, retire.