Democratic victories over Republican-drawn electoral maps just keep coming, and the impact could be even bigger than they hoped.

The latest: North Carolina lawmakers have just 2½ weeks to redraw all 13 of their congressional districts to be less partisan. Late Tuesday, a federal court struck down the GOP-drawn maps, saying Republican lawmakers violated the Constitution when they redrew many of the maps to lean so heavily in favor of Republicans.

It was the first time a federal court struck down a congressional map for partisan gerrymandering. North Carolina is one in a string of redistricting victories in the courts for Democrats, victories that could allow them to challenge other GOP-drawn maps and, potentially, draw maps more favorable to Democrats in time for the 2018 elections. Stephen Wolf with liberal politics blog Daily Kos estimates that in North Carolina, a nonpartisan map could give Democrats anywhere from two to five seats. Right now they control just three of 10.

Infusing politics in the map-drawing process is not new. It's something both sides have proved exceptionally skilled at when they have total control of states.

But successfully challenging maps because of their political intent is new. Until now, the Supreme Court has only struck down maps drawn based on race, but justices have recently signaled that they're willing to expand the reasons a map is unconstitutional. The court heard a case from Wisconsin last year that challenged Republicans' drawing of state legislative maps for being overtly partisan. This term, it will hear a similar case in Maryland, one of the few Democratic-drawn maps being challenged at the moment.

Republicans in North Carolina say they plan to challenge Tuesday's ruling, which could also send their case to the Supreme Court. There's another case in Pennsylvania being litigated in state courts that could strike down Republican-drawn maps.

“North Carolina had particularly stood out as an extraordinary aggressive partisan gerrymander,” said Rick Pildes, an expert on redistricting law at New York University. “You have a state that is essentially close to evenly divided in partisan terms, and yet the legislature managed to construct a congressional delegation that they thought would create a 10-3 Republican majority.”

Republicans may be victims of their own success, just by the sheer number of state legislatures they controlled after 2010, when maps were being redrawn based on new census data.

The party swept into state legislatures across the country in an effort to seize control in time to redraw electoral lines. (Most states allow state legislatures to draw maps, while a handful have nonpartisan commissions.) The plan worked. Republicans redrew nearly half of all congressional districts, four times as many as Democrats. And Democrats have been locked out of power in some key swing states since.

Democrats say that getting maps redrawn is a critical step to taking back the House, which they haven't controlled since 2010. It's also not an understatement to say that Democrats' political future could be on the line for the next decade if they don't have a say in how the next decade's worth of electoral maps are redrawn after the next Census comes out in 2020.

Winning governor's races is one way they had planned to put a stop to Republicans' map-drawing abilities.

But litigating these has been surprisingly effective. When a federal court threw out Wisconsin's state House map in November 2016, it was the first time in a decade that a federal court had done so because the maps favored  one party.

The Supreme Court has long been open to the idea that partisanship when drawing maps could be unconstitutional. In 1986, they said partisan gerrymandering in California amounted to a constitutional violation, Pildes said. But the justices couldn't agree on an objective way to measure partisanship. How much is too much, essentially?

Without such a measure, politicians in charge of the process have had no reason to draw nonpartisan maps. Pildes said in North Carolina, lawmakers stress-tested their maps to see whether the Republican districts could survive a surge of Democratic votes.

If the courts answer that question in 2018 — how much partisanship is too much — it could give Democrats an opening to challenge maps across the country and perhaps have a say for the first time in a decade over what legislative districts will look like for the next 10 years.