Like him or not, according to Simon Parkes, there was a plan to arrest everyone on Jan 20th but the Deep State threatened some kind of terrible retribution if that was attempted. I am thinking nuclear but don't know. As a consequence the plan was put on hold.

If they can do that once then it can be repeated as often as they like. Trump could easily be both impeached and imprisoned, or worse, before he has any chance to get back into office.