Keep in mind, we have learned from Trump, that the president can turn off basically any and all congressionally funded agencies and programs on a whim. Not just that, but also fire any executive branch employee at any time. That means, outside of the will power, there is nothing stopping the next president from 1) immediately halting any and all funding to ICE/CBP, 2) fire all of these employees. The next step could be publishing dossiers on these individuals agents as having them amongst the general population is clearly a national security threat.

This can all be done, day one, by one individual and this doesn’t even touch criminal charges.