The only option is to not elect someone that doesn't respect rule of law. And since I know some enlightened "centrist" will play the both sides game: What's 1 thing any previous president has done equivalent to violating posse comitatus.
Writing a rule that says the government can't do this is just the government writing a rule it can simply remove it ignore when inconvenient.
Just like Roberts schizo-rambling about the federalist papers and inventing new terms like "Core constitutional powers" while not addressing any of the dissents. Roberts pens in that the president gets broad immunity for "core" (defined nowhere) powers and ignores the public's interest in not having a criminal president.
Originalists like senile Roberts must have forgot the framers were literally escaping a monarchy with no judicial accountability. Maybe him and Alito can figure out the mental gymnastics needed to ask his wife to take down the stop-the-steal flag outside his house.