They can’t imprison all conservatives. They can demand that each person renounce conservatism or else face punishment. 90% will surrender their beliefs,and the remaining 10% will have their wealth seized and be imprisoned.
When the Union arrived in the South and occupied towns and cities during the Civil War, they demanded that residents of these towns take the Oath of Allegiance. Most signed it. Some didn’t, probably because of family connections or one thing or another.
In FLorida, there were some in West Florida who did have major slave plantations, some of them belonging to Andrew Jackson, but East Florida had a lower percentage of slave owners and just some people who weren’t supporting slavery but were just supporting their state (Florida was the third state to secede, but it had only been a state for about 15 years). So there was a lot of conflict.
Those who didn’t sign were exiled (often, not very far…for example, from St. Augustine to Jacksonville) and their property was seized. Much of this was later restored after the end of the war.
The only people imprisoned were those considered leaders who were in contact with more important Confederate honchos. Only a few were hanged, including Henry Wirz, a Swiss immigrant who was governor of Andersonville.
So that’s the pattern, but it was legitimate and actually, had Lincoln lived, it is thought that the reconciliation would have been much easier.
But the situation now is a unique situation. Nobody has rebelled against the government in the current case but are just asking for their rights. All conservatives are under attack and are now considered automatically enemies of the state. So I don’t know what’s going to happen, but giving in doesn’t help…and it doesn’t spare you, in the long run.