If the majority wants a certain government, how is the minority going to defeat them with guns? The majority will have more guns.
That's a good and necessary question.
If all it took to construct a building was to stack stones upon each other there would be no science of architecture and no point in writing The Fountainhead.
If all it took to fight a war was to use brute force without rational input there would be no science of warfare or any such thing as a military organization.
If all factors were equal in warfare then a simple majority of combatants would win every time. But in reality all factors are never equal. Thus the purpose of military science is to identify the factors that favor one side or the other and use or negate those factors to one’s advantage.
A book that covers this process is The Myth Of The Great War by John Mosier. In this work the author explains how the Central Powers managed to avoid defeat until the American entry into the WW1 even though they were outnumbered by the Allies.
Mosier also covers the role of the active mind in warfare:
Over at Pershing's headquarters, young ex-cotton dealer turned intelligence officer, Samuel Hubbard, looked at all the available information and concluded that the Germans were going to turn south, and launch an offensive across the Chemin des Dames at the end of May. Despite the fact that the Allied intelligence estimates had been continuously wrong for the last forty-five months of the war, Hubbard's analysis was disregarded. How could the Americans, who had just arrived on the scene, be better then the French and the British, who had been doing for it for years?
Mosier, who up to this point had been cataloging the effects of the unconscious approach to war as practiced by the Allied powers, says this:
On 27 May 1918, The Germans, to the consternation and surprise of everyone except Captain Hubbard, smashed across the ridge.
In order to succeed in business one has to possess valid knowledge and use an active mind. The same in true in the practice of warfare as demonstrated by Captain Hubbard. In warfare the active mind with valid knowledge as a general rule will prevail over those who practice blind obedience.
Now I must also point out that as long as one free to communicate then one is free to persuade members of a political majority that they have made an error.
And of course not everyone who votes for a state of tyranny, particularly if they've been bribed into it, is going to put their lives on the line for it. Right?