> we had a common enemy in communism

Communism wasn’t a “common enemy”, it was a boogeyman used as a cudgel by the government to strike down inconvenient dissent and ruin innocent peoples’ lives. There were plenty of Americans with Communist ideals, and plenty more who were branded as “communists” for suggesting such outrageous things as poverty reform or labor rights, including Martin Luther King Jr. See COINTELPRO and the Red Scare for examples of the government’s abhorrent treatment of suspected communists.