Apart from the lack of will among many in Congress, there's also the precedent of what happened to McCarthy in the Senate. Just like being afraid of being labeled a racist, people are afraid of being dismissed as being in favor of McCarthyism.
I think it should be required of every high school student in the US that they watch a truthful documentary of the life of Stalin, that they watch footage of USSR tanks in Czechoslovakia etc,, that they watch the tanks in Tiananmen Square, and that they read the Gulag Archipelago or something similar.