The ICE agents can't go around in cars clearly marked "ICE", because then the activists would easily harass them. These full-time professional activists follow ICE around all day harassing them.

You had four years of zero immigration restrictions or enforcement, completely open borders. Now we have the opposite extreme, max enforcement. Organized activists on the left are putting max pressure and harassment against ICE agents. They don't fear arrest because they know the courts are on their side. In the worst case, where they get arrested and then convicted, the next Democrat President pardons them on day one.

This is the natural end result of "zero penalties for harassing on-duty cops or government workers".

There is no way Trump manages to deport even 10%-20% of the illegals that were let in the past 4 years.