They won't be a regular army doing regular army stuff like taking land and stuff. They would be like the Taliban. How did that go again for the US? The Troubles were no picnic, look it up.

A militia made of a bunch of greasy brainwashed boomers

Put down by whom? The vast majority of the military and police force is right leaning. The would be ideologically compliant with the "greasy brainwashed boomers" they'd be putting down. If all the people who were trained on how to fight are on the "other" team... There's going to be a clear winner.

It would be an insane mistake to underestimate that group. Like the other comments said, they are the Taliban and the military/police. However even if they somehow weren't, it still means we have potentially tens of millions of domestic terrorists running around armed to the teeth and that's not a great feeling.

Would you really be down with dipshits like the proud boys and 3%ers acting like brownshirts and pulling a modern day krystallnacht? They already did a thing pretty damn close to the Reichstag Fire back in the beginning of 2021, and that crowd was not, shall we say, our best and brightest. You don’t have to be smart to be a thug.