This appears to be why Madigan can petition the Illinois Supreme Court

[LiberalFighter]

But still unclear on the rule or opinion she is relying. Could not find an Illinois law that covers the removal either.


Illinois Constitution

SECTION 6. GUBERNATORIAL SUCCESSION

(d) The General Assembly by law shall specify by whom
and by what procedures the ability of the Governor to serve
or to resume office may be questioned and determined. The
Supreme Court shall have original and exclusive jurisdiction
to review such a law and any such determination and, in the
absence of such a law, shall make the determination under
such rules as it may adopt.

[elleng]

1. Will look too;

where did you look?

(PS, I'm attorney, admitted in Illinois, but not practicing there.)

[LiberalFighter]

2. I looked at the Illinois Supreme Court website...

checked their Rules and the archived opinions. But, IMO their search engine is lacking.

Maybe you will have better luck.