The Teamsters, used to be a great union, but not anymore. The Mid-West union fund is messed up. Probably due to corruption. Currently there are only 2 union companies left in Cleveland, due to deregulation, and corruption, new hires are working 7 years, for 1 year of retirement benefits. The United Auto Works, and the unbelievable power they had, or still have, is part of why cars cost so much. But in some ways you can't blame them. They see a suit in the front office get a $500k bonus for saving the company a couple of million, and the guys in the pits are doing all the work.
As far as American unions go, they started out with good intentions, and to help the working man, but because of abuse and corruption, have become less and less helpful.