In the case of National Labor Relations Board v. Transportation Management Corp., 1982, the U.S. Supreme Court ruled in favor of the National Labor Relations Board (NLRB). The dispute arose when an employee was fired for union activities and filed a complaint with NLRB against his employer, Transportation Management Corporation (TMC). TMC argued that it had legitimate reasons to fire him unrelated to his union involvement. However, NLRB found that TMC's actions were motivated by anti-union sentiment and ordered reinstatement and backpay for the employee. On appeal, TMC contended that NLRB should have been required to prove its case beyond reasonable doubt rather than just preponderance of evidence which is a lower standard of proof. The Supreme Court disagreed with this argument stating that administrative proceedings are not criminal trials hence do not require proof beyond reasonable doubt but can be decided on preponderance of evidence basis.

In the dissenting opinion for the case of National Labor Relations Board v. Transportation Management Corp., Justice Powell, joined by Chief Justice Burger and Justices Rehnquist and O'Connor, disagreed with the majority's interpretation of Section 8(a)(3) of the National Labor Relations Act. They argued that it was not enough to show that an employer’s anti-union animus contributed to a decision to fire an employee; instead, they believed it must be proven that without such bias, the termination would not have occurred. The dissenters contended this standard better aligned with Congress' intent in drafting Section 8(a)(3), which aimed at preventing employers from interfering with employees’ rights but also recognized legitimate reasons for firing or disciplining workers. They feared that under the majority's "motivating factor" test, employers might face unfair labor practice charges even when their actions were justified by substantial business reasons unrelated to union activities.