[fruser1]

How much of the population do you need? I don’t know but here’s something on the American revolution, which did not have “massive” support in the colonies:

http://www.ushistory.org/us/11b.asp

[Smokin' Joe]

To accomplish anything meaningful? You'd need a minimum of 10%, and that with a reasonable and willing government.

For the American Revolution, it was about 1/3 loyalists, 1/3 patriot, and 1/3 on the fence. Without the French Fleet at Yorktown to stop the British from either reinforcing or withdrawing Cornwalis' forces, that might not have ended well. Up to there, it was a squeaker.