A more thorough explanation:

The Mark Hopkins Doctrine is a principle that applies to unemployment benefits in cases where an employee leaves a job due to a labor dispute. According to this doctrine, if an employee leaves their job due to a labor dispute, any subsequent employment they have must be genuine and intended to be permanent in order to avoid disqualification from unemployment benefits if they leave that job as well.

For example, let's say that an employee leaves their job at a factory due to a labor dispute. They then find a new job at a different factory, but they don't like it and decide to quit after a few weeks. If the new job was not a genuine attempt at permanent employment, the employee may be disqualified from receiving unemployment benefits.

The Mark Hopkins Doctrine was established in the case of Mark Hopkins, Inc. v. Employment Comm'n, where the court ruled that an employee who left their job due to a labor dispute was not entitled to unemployment benefits if they left their subsequent job voluntarily and without good cause.