COPPAGE v. KANSAS
A Kansas law banned "yellow dog contracts." These were employer agreements barring employees from joining a labor union. Coppage, an employer, fired an employee who refused to sign such an agreement. Coppage was charged and convicted of violating the Kansas law. He appealed.
Does the Kansas statute violate freedom of contract protected by the Due Process Clause of the Fourteenth Amendment?
Yes. The law was so arbitrary as to overcome the general presumption in favor of its validity. Legitimate exercises of the state police power could restrict freedom of contract, but there was no relationship here between the statute's purpose and the state's police-power goal.