Yes there is a far left fringe, but they are no where near as extremist as the right, and that extreme is the tea party, you are delusional if you think otherwise. Nothing wrong with a 2 party system, but when 1 of those parties starts letting a small amount of radicals control it, then the majority need to step up and put them in line. Only reason this small minority of tea party groups even got together is their staunch hatred for a black man in the white house.
As for John McCain, he has been a senator for a long time, and probably ready to retire, yet he wants to take over the GOP now? Stop sipping the tea, thats kind of ridiculous if you think about it. It is these rookie lawmakers that have no idea how to do their job, and have nothing to lose, that is trying to take over the GOP.