In one of the worst Supreme Court decisions in recent memory, the court has ruled that partisan gerrymandering is a political question that federal courts are not qualified or equipped to adjudicate.
Even if it's explicitly clear and empirical that a district has been drawn for partisan gain, the Supreme Court ruled that federal courts can't touch it.
From the Associated Press:
The justices said by a 5-4 vote on Thursday that claims of partisan gerrymandering do not belong in federal court. The court’s conservative, Republican-appointed majority says that voters and elected officials should be the arbiters of what is a political dispute. [...]
Chief Justice John Roberts said for the majority that the districting plans “are highly partisan by any measure.” But he said courts are the wrong place to settle these disputes.
In dissent for the four liberals, Justice Elena Kagan wrote, “For the first time ever, this court refuses to remedy a constitutional violation because it thinks the task beyond judicial capabilities.”
The only silver lining here is that state courts can still decide these cases and, since the Supreme Court has decided that federal courts can't touch it, state court rulings will be the final say.
Regaining total control of the federal government and successfully passing federal legislation to end gerrymandering feels like a longshot, but Democrats and anyone else who actually believes in democracy can also focus on regaining control of state legislatures, governors' mansions, and state supreme courts. States can also hold votes on ballot initiatives that will end gerrymandering.
Ironically enough, where this ruling by conservative justices will cause the most harm is in the most conservative states that will become even more hopelessly unequal and destitute. The most conservative states will elect the most conservative politicians who will redraw their districts to ensure that a permanent majority of right wing wackos hold power. And they will use their power to hollow out the government. Republicans won't be happy until their own strongholds become uninhabitable. And then they'll blame the rest of the world for it.