If I recall correctly, McCain has something like a 75% (middle of the road for Congress) rating with a major conservative watchdog. However, thats a per vote rating, not an issue based one. On the issues (gun control, GWs barely adequate tax cuts, immigration, ad nauseum), hes stabbed us conservatives in the back so many times that its hard to count. Fool me once, shame on you, fool me twice (or three or four or more realistically 10), shame on me.
It's not just a question of who is further left. How can we trust a man who has pulled dirty tricks on his "partners" so many times? The following quote was about national enemies, but would apply just as well to this situation:
A nation can survive its fools, and even the ambitious. But it cannot survive treason from within. An enemy at the gates is less formidable, for he is known and carries his banner openly. But the traitor moves amongst those within the gate freely, his sly whispers rustling through all the alleys, heard in the very halls of government itself. For the traitor appears not a traitor; he speaks in accents familiar to his victims, and he wears their face and their arguments, he appeals to the baseness that lies deep in the hearts of all men. He rots the soul of a nation, he works secretly and unknown in the night to undermine the pillars of the city, he infects the body politic so that it can no longer resist. A murder is less to fear. - Marcus Tullius Cicero
Another major problem with those ratings is that many politicians will vote with their supposed constituents when their vote won't matter, and only vote against them when it actually counts. I'm sure that there have been more than two issues since 2001 that came down to the last vote, but on the two that I know of (ANWR and G14) McCain was on the wrong side.
Frankly, I'd like to see the rules changed so that congresscritters' votes on an issue would remain confidential until after voting was done. That would require that any politician who wanted to back-stab his constituents would have to risk either (1) having the outcome his constituents would favor prevail when he could have had his own outcome prevail instead, or (2) having his vote against his constituents exposed even in cases where it didn't actually do him any good.
BTTT