Literally it’s more like “non-speakers”, though, isn’t it? Nie + mowić = Not + to speak.
So, maybe in contemporary Polish the word has been polished to mean “mute”, but could be that they were “those damn non-speakers [of our Polish] across that river-thing!”
Not in US politics. If you have 51% of votes of whoever is The Party at the moment, you can make decisions without others impeding on them.
If one party got 51 % of votes, then that means 26,01 % of all votes is enough to decide about the all of the country’s things alone.
At least Wiktionary completely agrees with you!