Garner v. Board of Public Works, 341 U.S. 716 (1951), is a ruling by the United States Supreme Court which held that a municipal loyalty oath which required an oath and affidavit about one's beliefs and actions for the previous five years and which was enacted more than five years previous is not an ex post facto law nor a bill of attainder.

They sued for back pay and reinstatement in their jobs, claiming that the oath and the affidavit they were required to execute constituted a bill of attainder and an ex post facto law.

In three sentences, Clark held that since past actions and beliefs may impugn present fitness for duty, the affidavit was justified.

[4] Clark distinguished United States v. Lovett, 328 U.S. 303 (1946), which was not a general law establishing qualifications for office but which specifically named certain individuals and required their separation from government service.

[5] Petitioners had argued that the charter amendment required scienter (knowledge that the organizations they belonged to did, in fact, advocate the violent overthrow of the government or a communist political philosophy).

Under the Court's decisions in United States v. Lovett, Ex parte Garland, 71 U.S. 333 (1867), and Cummings v. Missouri, 71 U.S. 277 (1867), Burton concluded, the oath as currently framed was an ex post facto law and a bill of attainder.

The Maryland law in Gerende was limited to actual acts of violence or overthrow, while the Los Angeles ordinance was not.

[17] Second, Black believed that the majority's decision in Garner significantly weakened the Court's holdings in Ex parte Garland, Cummings v. Missouri, and United States v.