"If McCain is the Republican candidate I'll vote for the Constitution Party. McCain is a major RINO."
That's your privilege. If you like "President Hillary Clinton" go right ahead. Like I said you will be cutting off your nose to spite your face. Go for it. That's your right under our democratic system.
Given that the Republicans in Congress would let "President Hillary Clinton" get away with far less leftist nonsense than "President George W. Bush" or "President John McCain", then I would have no compunction about going right ahead and voting Constitution Party.