A more thorough explanation:

The Marcus Model is a method used in labor law to determine whether a union member's state-law claim against their employer is preempted by federal law. This means that the federal law takes precedence over state law in certain situations. The Marcus Model focuses on whether the state-law claim can be maintained independently of an interpretation of the collective-bargaining agreement.

For example, if a union member files a state-law retaliatory-discharge claim against their employer, the Marcus Model would be used to determine whether this claim is preempted by federal law. If the claim can be resolved without interpreting the collective-bargaining agreement, it is not preempted by federal law.

There are at least two models for applying the Marcus Model: the White Model and the Marcus Model. The White Model focuses on whether the claim is negotiable or nonnegotiable, while the Marcus Model focuses on the independence of the claim in relation to the collective-bargaining agreement.

The Marcus Model is named after Stephanie R. Marcus, who proposed the model in a law-review note in 1989.