So argues Tom Woods in this highly informative Von Mises Institute article.

Unions make a few people better off (especially the union leaders!) but their depredations against capital and productive efficiency make many others (mostly poorer people) worse off. And their political agenda of promoting welfarism, the growth of government, and hindering free trade greatly compounds the harm.

Long ago, Big Labor made an alliance with the Democrats, who gave them the special favors it wanted (such as the “right” to represent people who didn’t want anything to do with unions) in return for money and campaign muscle.

Woods quotes Professor Morgan Reynolds’ whose book Making America Poorer gets things exactly right: through their interference with the free market, that’s what unions do.