In the event Mueller does find substantial evidence of Trump's criminality but feels obliged to

[TomSlick]

6. I agree.

Unfortunately, the only way to force the issue on SCOTUS is for the grand jury to subpoena - Trump refuse to comply - the District Court rule - the Circuit Court of Appeals rule - only then will SCOTUS rule. (It is possible SCOTUS could reach down and take the case from the lower courts but that is unlikely.) It seems unlikely this would happen quickly.

My hope is that Trump would decide it would be politically untenable to defy a subpoena. However, I think if I was Trump's lawyer (God forbid), I would advise defying the subpoena and slow walk my way through the courts. If Trump ever appeared in front of a grand jury - whether sooner or later - I would advise him to plead the Fifth Amendment, the politics be damned.