So, for instance, no gay pride demonstration was ever a legitimate protest?
Some revolutions were carried out by less than that percentage.
I should clarify that I don't mean to say that this makes the protest valid, just that the argument that protest is only acceptable if an arbitrary number of people are involved is not all that good.
10% of people oppose nearly everything and it isn't tyranny so, unless you're an anarchist, your point is ridiculous.
I think this quote from Tocqueville explains it well: "So what is a majority taken as a whole, if not an individual who has opinions and, most often, interests contrary to another individual called the minority. Now, if you admit that an individual vested with omnipotence can abuse it against his adversaries, why would you not admit the same thing for the majority? Have men, by gathering together, changed character? By becoming stronger, have they become more patient in the face of obstacles?"
What matters is not how many supporters each side has but what the merits and demerits of each side are.
You could argue that consent, as traditionally understood, doesn't even meaningfully exist in a population above a certain threshold (say 10^6). Consent implies knowledge and understanding, in a population of 10^6 and up, in even a moderately complex environment, there is no way even 1/10 of the population understand more than their own very narrow slice of what their environment and society are doing.
