You can read about what is and isn't allowed here: https://www.nlrb.gov/about-nlrb/rights-we-protect/the-law/discriminating-against-employees-because-of-their-u

You can read about what is and isn't allowed here: https://www.nlrb.gov/about-nlrb/rights-we-protect/the-law/discriminating-against-employees-because-of-their-union https://www.nlrb.gov/about-nlrb/rights-we-protect/the-law/di... You might also be interested in reading about why the NLRB was formed: https://en.wikipedia.org/wiki/National_Labor_Relations_Board https://en.wikipedia.org/wiki/National_Labor_Relations_Board Basically we have a lot of rules about the relationship between unions and companies because when we didn't do that there was a lot of violence.