No, I disagree. If things are really fucked (as they are) 30% of a population is more than enough to enact change. If they are really motivated to do so. Get most of those 30% only the street and you see what power it has.

Of course with 80/90% it’s easier. Much much easier but that’s just fantasy land. You can get 90% of the population to agree on many basic facts, so you can forget about having then agree to protest together.

Plenty of revolutions were made, and dictatorships overturned with much fewer people on board.

I very much disagree on how much power 30% of the population has. Yes the electoral system you have in the USA is beyond stupid. However voting is only the easiest and most polite way to make change.

Go on strike, protest, build some guillotines. If the population really wants it, change will be made, even if it’s only 15/30%. Because the remainder of that population will not opposite necessarily. They just don’t care enough to protest.