The postulation works both ways:
If Americans are too chicken to fight against federal gestapo thugs, then those same Americans are too chicken to pound on doors and demand that people surrender their weapons.
Nobody can guess what will happen until it happens. It’s all conjecture.
The only American example we have of what happens when the federal government declares war on its citizens is the Civil War when the army broke in two and we had a war.
The other example we can look at is Libya. When Kaddhafi ordered his army to attack Libyans, more than 75% deserted and returned to their provinces to protect their families. Kaddhafi and his elite mercenaries ended up dead after the deserters joined with the provincial militias and wiped them out.
I worry about that. At the most simplistic level, all political systems are either Collectivist or Individualist. Socialists, Communists, Fascists, and Democrats are all Collectivists. There are few examples of Individualists systems -- what we are trying to preserve is perhaps the only one.
Men in a collective can do very bad things -- peer pressure, shared, guilt, whatever. Groups do things that individuals will not do (are unwilling to do). Will a group of cowards pound on a door and take away a father from a screaming family? Yes, a group of cowards will do that -- because they are a group.
So the question is: Will an individual stand strong against tyranny, even when it travels in packs? Some indivuals will, certainly. But as many men have become neutered, the pool of courageous individuals declines -- but the mass of cowardly group-thinkers who will do anything they are told to do is probably about as large as ever. That's bad.
Kaddafi ended up dead after Obama intervened with air power, weapons, technical support, and covert boots on the ground. Without that intervention, Kadaffi would likely still be in power.
Have you forgotten WACO? After all, it was for the children!