You don't have to be wrong on the internet. You can just look things up.
What would become known as the McCarthy era began before McCarthy's rise to national fame. Following the breakdown of the wartime East-West alliance with the Soviet Union, and with many remembering the First Red Scare, President Harry S. Truman signed an executive order in 1947 to screen federal employees for possible association with organizations deemed "totalitarian, fascist, communist, or subversive", or advocating "to alter the form of Government of the United States by unconstitutional means."
So it wasn't just the Tankies, it was all communist since communism demands a stateless society.