Many psychological experiments have shown that most people when ordered to do something by a person they perceive as an authority will follow those instructions even in cases where they feel the instructions are wrong. Most people just want to keep their head down and do their jobs. So yes, if Trump ordered them to, most rank and file would commit illegal actions. While I’d like to think most wouldn’t be willing to murder someone, we’ve seen ample evidence that there are enough that follow Trump that would be more than willing to for someone to do it, and most would be unwilling to stop them even if they weren’t willing to do it themselves.

We have seen all this before. Hitler didn’t start off by committing genocide, Stalin didn’t start by sending people to gulags. They start small with the things people are willing to do even if they feel it’s wrong and slowly escalate. Stripping rights turns into imprisoning, which turns into murdering, and each step of the way everyone either says “I’m not doing it myself, I’m not responsible” or “They deserve it because they’re a <minority> and I’m not”.