Noerr–Pennington doctrine.The principle that the First Amendment shields from liability (esp. under antitrust laws) companies that join together to lobby the government. • The doctrine derives from a line of Supreme Court cases beginning with Eastern R.R. Presidents Conference v. Noerr Motor Freight, Inc., 365 U.S. 127, 81 S.Ct. 523 (1961), and United Mine Workers v. Pennington, 381 U.S. 657, 85 S.Ct. 1585 (1965). [Cases: Civil Rights 1374; Constitutional Law 91. C.J.S. Civil Rights §§ 143–144, 146, 157, 160; Constitutional Law §§ 461–462, 466, 612–629.]

[Blacks Law 8th]