I think that a very important distinction is that the settlers/founders built what they knew of as America and their enemies were (mostly) physically in England. Call that a home field advantage or whatever, but they had more support than they otherwise would have.

In the modern case, Antifa hasn't built shit. They only destroy. Everybody hates them except the 'leaders' of the cities were they run wild.

If we had a "Purge" night in Portland, there would be no Antifa in the morning.