John McCain will be an 80-year-old senator if he wins re-election to a sixth term.  But the octogenarian senator has far more to deal with than questions about his age. Several conservative PACs have already targeted McCain for defeat, notably the Senate Conservative Fund and the Club for Growth.  With the right sharpening its knives to bring him down, the question of his survival in a Republican primary can't be dismissed. The Hill: “There are few Republicans who have betrayed our conservative principles more than John McCain,” SCF President Ken Cuccinelli said in an email to supporters Tuesday of the party's 2008 nominee for president.  “John McCain lost his way a long time ago and it's time to replace him with a strong conservative leader who will support and defend the Constitution.”  Cuccinelli’s email links to a petition to replace McCain, which, as of 2 p.m. ET, has 457 signatures. He...(Read Full Post)