That assumes your union rep is inclined to help you. In practice (not principle), they have the same incentives as the other managers and HR do in this story. The union rep could decide that the harasser is more important to their union, politically, than you are, and decide not to take action.
Plus, the union can simply terminate your membership as retaliation. For a closed shop, that's equivalent to firing you, but without many of the legal protections that come against wrongful termination.
That's not a matter that's specific to a particular country, though. It's inherent in the nature of a union structure (and arguably inherent in the nature of any hierarchical human structure, which is a superset of "unions").
You can find situations like the one I described in any country, not just the US.
Contact your state's labour commissioner. If you received stock or stock options, contact your state securities commissioner. Otherwise, suing is tried and true.
I wasn't aware that spez was co-CEO with ekjp... I thought he only became CEO afterwards. Even if the board/spez forced her to make all of the unpopular decisions (there were many), the buck still stopped with her as the CEO[1], fall-woman or not. Also, why did spez want Victoria gone? He made Ellen Pao fire her too, right?
1. https://www.reddit.com/r/announcements/comments/3cbo4m/we_ap...
https://www.reddit.com/r/TheoryOfReddit/comments/3d2hv3/kn0t...
Note, I'm not affiliated with Pao, I just thought her treatment by the reddit community was extremely disappointing.
I understand that English has absorbed that word and its meaning in the current sense. But please don't use that word. That is like the n-word in south india. It is specifically used to refer to people in a derogatory way.
Your manager is engaging in harassment, HR is where you "should" raise this. Her following protocol also makes her case stronger I would argue. You gave your company the chance to make things right. After that I'd say the gloves could come off if that's the route you want to go.