Required union membership is negotiated in the union contract under the clause of "closed shop."  I don't get why people who CHOOSE to work in a closed union shop late, like Dick, bash organized labor for collective bargaining pay raises, bennies, and retirement.  The anti-union crowd want something for nothing.  If you don't like or support organized labor then stay the hell out of those workplace environments.  Union need a strong workforce that has respect and supports what the union does for them.