He is responsible for it.
The HUAC could have suspended the investigations at any time. Why didn't they?
they did...
Following Senator McCarthy's censure, however, and his subsequent departure from the Senate, the American public grew increasingly wary of the "redbaiting" techniques employed by HUAC and others. The work of the committee continued to decline in importance throughout the late 1950s and early 1960s until the committee itself was renamed the House Internal Security Committee in 1969, prefiguring its eventual abolition in 1975.