companies were now able to ship their operation to mexico, etc.. and then say "Well we'd love to keep our jobs in the US, but the union is being unreasonable in their expectations"

and just the general not being able to compete with cheap labor on a global scale.

the less power unions had to stop the bleeding, the more easily they're seen as just a greedy, corrupt, ineffective, antiquated institution and not much more than another special interest group who's time has passed. people repeat ad nauseam that the unions are to blame, and unions are a bad thing. it starts setting in peeople's heads... they become easy scapegoats along with immigrants, welfare, etc...

i'm talking out of my ass a bit, but i do think its a decent size factor