NLRB just changed a key rule so a lot of union-busting by the employer now essentially automatically forces recognition of the union.

https://www.nlrb.gov/news-outreach/news-story/board-revises-...

Again, that's a nice rule. But how is that enforced? It still has to be proven that RTO is intended to union bust. That's the tough part.

To my understanding if 50% (a majority) of the employees signs up (ie, union cards) for the union prior to any vote, if the employer takes a union-busting act, the union is automatically legitimized and the employer must negotiate with them.

Most major corporations are all already doing union-deterrence (not illegal) as operating practice so they likely won't see an impact unless there is a black swan event that causes workforce and management to come to loggerheads.

Your understanding is correct.

https://www.nlrb.gov/news-outreach/news-story/us-circuit-cou... ("U.S. Circuit Court Directs U.S. Marshals to Take Haven Salon + Spa Corporate Officials into Custody for Refusing to Comply with Board’s and Court’s Orders")