The 1965 U.S Supreme Court ruling in Albertson v. Subversive Activities Control Board saw much of the act's Communist registration requirement abolished.

'[4] Furthermore, members of 'Communist-Action Organizations' including those of the Communist Party of the United States of America were required (prior to a 1965 Supreme Court case mentioned below)[5] to register with the U.S. Attorney General their name and address and be subject to the statutes applicable to such registrants (e.g. being barred from federal employment, among others).

[6] In addition, once registered, members were liable for prosecution solely based on membership under the Smith Act due to the expressed and alleged intent of the organization.

"[9] It tightened alien exclusion and deportation laws and allowed for the detention of dangerous, disloyal, or subversive persons in times of war or "internal security emergency".

By March 1, 1951, the act had excluded 54,000 people of German ethnic origin and 12,000 displaced Russian persons from entering the United States.

[11] The Act made picketing a Federal courthouse a felony[12] if intended to obstruct the court system or influence jurors or other trial participants.

For example, in Galvan v. Press,[23] the Court upheld the deportation of a Mexican alien on the basis that he had briefly been a member of the Communist Party from 1944 to 1946, even though such membership had been lawful at that time (and had been declared retroactively illegal by the Act).

The 1964 decision in Aptheker v. Secretary of State ruled unconstitutional Section 6, which prevented any member of a communist party from using or obtaining a passport.

In 1965, the Court voted 8–0 in Albertson v. Subversive Activities Control Board to invalidate the Act's requirement that members of the Communist Party were to register with the government.

[24] In 1967, the act's provision prohibiting communists from working for the federal government or at defense facility was also struck down by the Supreme Court as a violation of the First Amendment's right to freedom of association in United States v.