<P> First, since the Clayton Act 1914 § 6, there is no application of antitrust laws to agreements between employees to form or act in labor unions . This was seen as the "Bill of Rights" for labor, as the Act laid down that the "labor of a human being is not a commodity or article of commerce". The purpose was to ensure that employees with unequal bargaining power were not prevented from combining in the same way that their employers could combine in corporations, subject to the restrictions on mergers that the Clayton Act set out . However, sufficiently autonomous workers, such as professional sports players have been held to fall within antitrust provisions . </P> <P> Second, professional sports leagues enjoy a number of exemptions . Mergers and joint agreements of professional football, hockey, baseball, and basketball leagues are exempt . Major League Baseball was held to be broadly exempt from antitrust law in Federal Baseball Club v. National League . Holmes J held that the baseball league's organization meant that there was no commerce between the states taking place, even though teams travelled across state lines to put on the games . That travel was merely incidental to a business which took place in each state . It was subsequently held in 1952 in Toolson v. New York Yankees, and then again in 1972 Flood v. Kuhn, that the baseball league's exemption was an "aberration". However Congress had accepted it, and favored it, so retroactively overruling the exemption was no longer a matter for the courts, but the legislature . In United States v. International Boxing Club of New York, it was held that, unlike baseball, boxing was not exempt, and in Radovich v. National Football League (NFL), professional football is generally subject to antitrust laws . As a result of the AFL - NFL merger, the National Football League was also given exemptions in exchange for certain conditions, such as not directly competing with college or high school football . However, the 2010 Supreme Court ruling in American Needle Inc. v. NFL characterised the NFL as a "cartel" of 32 independent businesses subject to antitrust law, not a single entity . </P> <P> Third, antitrust laws are modified where they are perceived to encroach upon the media and free speech, or are not strong enough . Newspapers under joint operating agreements are allowed limited antitrust immunity under the Newspaper Preservation Act of 1970 . More generally, and partly because of concerns about media cross-ownership in the United States, regulation of media is subject to specific statutes, chiefly the Communications Act of 1934 and the Telecommunications Act of 1996, under the guidance of the Federal Communications Commission . The historical policy has been to use the state's licensing powers over the airwaves to promote plurality . Antitrust laws do not prevent companies from using the legal system or political process to attempt to reduce competition . Most of these activities are considered legal under the Noerr - Pennington doctrine . Also, regulations by states may be immune under the Parker immunity doctrine . </P> <Ul> <Li> Professional Real Estate Investors, Inc., v. Columbia Pictures, 508 U.S. 49 (1993) </Li> <Li> Allied Tube v. Indian Head, Inc., 486 U.S. 492 (1988) </Li> <Li> FTC v. Superior Ct . TLA, 493 U.S. 411 (1990) </Li> </Ul>

Three political factors that influence the inconsistent enforcement of antitrust law over time