Truly the pioneer of the modern GOP.
You say that like its a bad thing.
Seriously thought he was concerned about communist infiltration of government and its toleration by the Democratic party. Just consider some of the damage done by communist agents in the 1940s. They were responsible for helping the Soviet Union obtain nuclear weapons giving them a stronger military position.
They were also responsible for pushing US policy in China towards abondoning and undermining Chiang Kai-shek thus helping Mao to take over China. Imagine how much happier and more prosperous the people of China would have been. In turn that would have enabled the South to win a clear victory in the Korean War reuniting the peninsula. I suspect it would also given the French a much better chance of beating the Vietnamese communists in 1954. Just imagine for a moment how much better off and happier those two countries would have been if the South Koreans and French had managed to do what the British did in Malaysia and eliminate the communists.
Communist agents and fellow travellers in 1940s US caused incalculable human misery that still continues to this day and Joe McCarthy was a hero for working to expose them.