Many private sector unions would not formally endorse the idea of a general strike out of fear of being of sued by their employer, but workers without formal endorsement of their unions could engage in wildcat strikes by simply deciding to walk out individually.
"If the unions do not make a formal call for a general strike, it probably avoids a Taft-Hartley issue," says Don Taylor, an assistant professor at the University of Wisconsin School of Workers.
In order to create conditions in which workers might walk out of work on a type of general strike, there has to be a great deal of discussion in the progressive and labor movement by organizations encouraging them to do that. If most of these online-based DC advocacy organizations wanted to show true solidarity with the protesters in Wisconsin, they would send out emails to their millions of members educating them about the possibility of a general strike in order to save collective bargaining in Wisconsin. Unlike unions, these organizations could legally do this under Taft-Hartley since they are not trade unions.
If the large progressive advocacy organizations were willing to educate workers and activists about how to organize a general strike, it could spur on a dramatic people-powered political act not seen since the 1930s. Does Wisconsin represent the birth of a new, powerful progressive movement or is it simply the last violent, desperate gasps of air of a dying movement?
http://www.alternet.org/news/150134/the_wisconsin_uprising_is_a_bottom-up_movement_--_should_we_hope_dc_leaders_don't_get_in_the_way?page=entire