He's probably about as safe as anyone can be. A sitting US senator is among the most powerful people in the world.
Would Trump gladly imprison Van Hollen in a foreign concentration camp? Absolutely.
We're not there yet, and acts of resistance, no matter how small, are how we prevent us from getting there in the first place.
I agree with everything you said. None of us knows what might happen.
But for everyone out there screaming "Do something!" (Myself included), this is undoubtedly something.
The alternative is to do nothing in fear of what Trump might do.
That's what Trump wants. He has the power that he's given. To acquiesce is to grant him power.
That's what every law firm and university that's capitulated to Trump has done, so I'll support Van Hollen's open defiance any day of the week.