Per the linked articles, unions are intertwined with the corruption. This wouldn’t be the case if unions were politically touchable. As long as there enough voters who will always say, “unions aren’t the problem”, they will be part of the problem. They get money for nothing and nobody blames them.

It is curious how unions in America behave so very differently to unions in other places. American unions almost universally seem to be short-sighted and completely protectionist. This isn't the case in western Europe, so it doesn't seem to be inherent to a union.

This creates a communication hurdle between Europe and America. The expectations of what a union does differ so much, you could say Europeans and Americans mean a totally different thing when using the same word.

Unions get money to fund lawyers to protect their members, and to be able to go on strike. This protection and feedback is essential for preventing companies from taking advantage of their employees.

The increasing inequality in the US can in large part be attributed to corporations winning the war against Unions. Corporations have been ruthless towards this end, including funding think-tanks that gaslight Americans.