Even though the unions were in a much more vulnerable position; one would have figured civil disobedience would have been the most effective way to protest the Nafta treaty and other trade agreements which were passed or amended during the Clinton administration. The rationale was always if you don't agree with us; then it will be much worse under a Republican administration. When Reagan wa sPresident many of the union leaders enjoyed far more the perks his Republicans offered than any meaningful representation of the unions.
Also, a recent scandal (maybe two weeks old, funny that it got out just before the big strike) is that an important member of the bosses' union MEDEF, Gautier-Sauvignac, was taking huge amounts of cash from the unions account ; conservative newspapers insinuated that some of that cash was going to the labor union leaders... Auferre, trucidare, rapere, falsis nominibus imperium; atque, ubi solitudinem faciunt, pacem appellant.