Gerrymandering is a tough one. Both sides do it whenever they have the opportunity.
State Legislatures generally have wide latitude to draw district lines.
Wouldn't it be incumbent upon the plantiff to prove significant harm recognized by current laws, violation of state law, or violation of state constitution in state court?
Courts can't draw district lines. They can only send it back to the state legislature to redraw the districts to relieve harm, illegality, or unconstitutionality.
The US Supreme Court could only rule that Laws of Congress or The Constitution were violated, and kick it back to the state legislature to correct.
Courts don't legislate.