Guardrails? I think you should re-read their decision again. They gave him protection because until now even official acts didn’t necessarily protect the president. And now, it doesn’t matter what illegal thing he does as long as it’s part of an official act. ANYTHING. Because as long as it’s part of an official act they can’t even question it. And they didn’t even provide a list of what constitutes an official act.

So they literally put the president above all laws provided he can tie it back to some vague notion of an official act.