The Red Scare (n.) was the domestic half of the invasion of Russia: one front stopped the appeal being made, the other stopped anyone at home answering it.
Red Scare (n.) rested on the principle that the state may prevent improper thought and its expression — and used it to break the unions.
Red Scare (n.) was business's answer to a labor movement drifting left: weaken the unions, break the radical parties, and frighten the liberals.
Red Scare (n.) that Woodrow Wilson ran made the Patriot Act look like a tea party, jailing even the mainstream labor leader Eugene Debs for questioning the war.
A Red Scare (n.) suspends the demand for evidence: defectors, informers and opportunists become experts, and stay experts even after they are exposed as liars.
A Red Scare (n.) has a record of service: 1919's broke the postwar union drives, and the Truman-McCarthy scare launched the permanent war economy and weakened the New Deal coalition.