"Don't worry, if the president imprisons his political enemies, you can still get a writ of habeas corpus."
"But to prove that's why you've been imprisoned requires proof of..."
"Presidential motive!"
"And under Trump v US, presidential motive is..."
"Inadmissible!"
I'm actually not as sure on this part. The ruling clearly says you can't use such evidence in a prosecution of the President; I'm not sure if it means such evidence can't be used in any other proceeding (though, of course, that's not foreclosed here).
It will be colored based on whether they want to go to war with Trump. I can skip to the end on this one, not one of those six has the courage to start that fight.