A new report on unions from the Economic Policy Institute examines the effects and details of unionization. Organized labor is part of how the many have organized against the few, so it makes sense that that’s been attacked throughout history.
The United States has a notably violent labor struggle, even during the days of struggle to outlaw child labor. Left-wing groups (often unionized) then went on to become a strong force against big business in the U.S. during the Great Depression. That’s a major factor of why the anti-union Taft-Hartley Act of 1947 was passed.