Obviously you're grasp of documented history is seriously flawed. He ultimately got into a feud withe the Army and accused one of Joseph Welch's attorneys of having communist sympathies. In a televised encounter where McCarthy made his accusation Welch famously responded "Until this moment, Senator, I think I never really gauged your cruelty or your recklessness." When McCarthy continued his attack Welch angrily responded "Let us not assassinate this lad further, senator. You have done enough. Have you no sense of decency?" This was the straw that broke the public support's back and since he had already been ostracized by even his own party his power was over. He died three years later a broken man.He was an alcoholic who consistently violated citizen's Constitutional rights, was eventually disgraced, made politically impotent and died not long afterwards from acute hepatitis due to his alcoholism. He was able to get away with it for so long because of the Red Scare but eventually he went after the military, that's when public opinion turned against him.
Really?
Myth aside, name an American that Joe McCarthy violated the constitutional rights of? I would really like to see something other than slander on this?
Public opinion turned against him when America's own Josef Goebbels, Edward Murrow engaged in a prolonged smear campaign against him without the need for actual evidence. Kind of like you are doing here.