Complex sentence: The court reversed itself in 1967 with its decision, in "Afroyim v. Rusk", that section 401 of the Nationality Act of 1940 is unconstitutional because the Fourteenth Amendment prevents Congress from taking away citizenship without the citizen's assent.
Split into simpler sentences: The court reversed itself in 1967 with decision, in "Afroyim v. Rusk". It called section 401 of the Nationality Act of 1940 unconstitutional and stated that the Fourteenth Amendment prevents Congress from taking away citizenship without the citizen's assent.