Tuesday’s special election to fill a vacant congressional seat in suburban Atlanta was a rare electoral moment not just because $50 million in spending made it the most expensive campaign ever for a seat in the House of Representatives. It was unusual because either party had a realistic chance to win.

That’s not true in much of the nation, where election districts are drawn to virtually guarantee that one party will win. That kind of thumb on the scale is a big reason for our polarized politics. The situation is so bad that the U.S. Supreme Court announced on Monday it will review an outrageous example of gerrymandering in a Wisconsin redistricting plan that ensured more Republican winners for the state Assembly than Democrats.

The case, which will be argued this fall, could be one of the most important ones for voting rights and election law in three decades. As with any case, however, it’s unclear how far the justices will go to stop gerrymandering, the root cause of many of the nation’s ills.

The court has invalidated districts drawn to dilute the strength of black voters, but never has voided redistricting plans based on political partisanship. And while the court has said such political imbalances might be unconstitutional, it has not provided a clear standard to determine when the scales got tipped too far in favor of one party. In Wisconsin, where elections can be close, a federal appeals court found that the GOP-controlled legislature drew its 2010 district map to consolidate an unfair advantage.

The time has come for the nation’s top court to provide such standards before the once-a-decade maps are redrawn after the 2020 census. But agreeing to review the Wisconsin case took only four votes. The justices then split 5-4, with the conservatives putting on hold the lower court ruling that new maps must be drawn immediately.

Cramming too many voters of one party into an election district results in representatives who do not have to moderate positions or seek compromise. Knowing re-election is all but certain, it can make them unresponsive to voter demands and breed corruption.

Isn’t America all about fair fights?