As an aside, I’m slightly skeptical about unions in the US. The US’s economic model seems to be based around innovation and unions arguably make making decisions slower and more difficult.
If you look at Germany’s economic model, one with very strong employee protection, it seems largely based on pre existing industries. Yet the US’s seems more based on innovation and failing fast. And German political culture seems more consensual compared to US political culture.
Of course, this doesn’t mean I don’t think unions are possible or a good idea in the US—for certain industries I think they could alleviate the US’s problems—but I just doubt they’ll readily get government backing, support or favorable legislation in the short term.