Felix Frankfurter,
Algoma Plywood Veneer Company v…
“ The term 'unfair labor practice' is not a term of art having an independent significance which transcends its statutory definition. The State are free (apart from pre-emption by Congress) to characterize any wrong of any kind by an employer to an employee, whether statutorily created or known to the common law, as an 'unfair labor practice.' At the time when the National Labor Relations Act was adopted, the courts of many States, at least under some circumstances, denied validity to union-security agreements. ”
