The problem with unions is their harm is invisible to supporters. They see higher wages for union members and think it's a free lunch. But what they don't see are the jobs lost or the people locked out. Thats baked into union history, many early unions were explicitly formed to keep newly freed black slaves and immigrants from competing with white workers. Labor's golden boy Samuel Gompers openly opposed Chinese immigration for exactly that reason.
But as you can see, he doesn't mean all workers. He means some workers at the expense of other workers. Now strip away the race and make both groups white. It's still one group locking another out of opportunity, still insiders protecting themselves at the expense of outsiders. The injustice of it doesn't vanish because the skin color matches - the harm is built right into the model.
He explained that “World experience has demonstrated that the white race cannot assimilate races of other colors—we already have one race problem unsettled.”14 Like many discussions of immigration in the Federationist, Gompers’ editorial began with a discussion of economics and ended with a race-based justification. Ironically, one year later, in May 1919, Gompers was chosen presiding officer of the International Commission for Labor Legislation at Versailles, which offered a list of necessary conditions for a “better life for all workers.”
But as you can see, he doesn't mean all workers. He means some workers at the expense of other workers. Now strip away the race and make both groups white. It's still one group locking another out of opportunity, still insiders protecting themselves at the expense of outsiders. The injustice of it doesn't vanish because the skin color matches - the harm is built right into the model.