Since the Court has no executive authority of its own, if the Chief Executive chose to defy it, to whom would it turn for enforcement?
I'm a bit rusty on this, but I remember back in colleg being told that courts are empowered (ironically by the executive) to have officers carry out their orders i.e. A bench warrant in which officers must arrest someone, or in some courts even their own marshalls.
Its why a judge can hold elected officials in contempt or arrest them.
I'm trying to remember the exact wording but it had to do with Bush vs Gore, and most of the liberals in my class arguing that Bill Clinton had the right to refuse to follow SCOTUS and stop the re-count and to go their and seize the ballots and have them re-counted.
The little commies were arguing that Clinton as chief executive and enforcer of the constitution had a right to over rule or ignore SCOTUS since they felt scotus had made the wrong decision and that Clintons interpretation of the constitution and duties allowed him to as he wished and there was nothing scotus could ever do to stop him.
I laugh about it now, since its pretty clear these idiots weren't thinking long term, and I'm sure they are all holding different opinions today.
The closest the Supremes could get to enforcement would be to ask the Congress to impeach the POTUS.