After Virginia, the Democratic Party is breathing a sigh of relief. The rather easy victory for Governor-elect Ralph Northam stems the tide of recent hemorrhaging of key positions across the United States to Republicans, and continues Democrats’ control over a blue-ish state. Northam’s victory, and that of Justin Fairfax, the second black official elected in a statewide race in Virginia, also offers a sign that virulent and race-baiting white-identity politics—politics that characterize the Trump era and the late portion of Republican Ed Gillespie’s campaign—are beatable, even in the cradle of the old Confederacy.

Those signs are reason enough for Democrats to celebrate. But the true national significance of Northam’s victory, as well as of major gains by the party in the General Assembly, might not be in the message they send, but the fact that those gains constitute the first big victory for Democrats in the political mapmaking game in at least a decade.

Republican hegemony in the decennial political-redistricting game is well documented. The competition to control just who draws each state’s political maps has taken shape as an arms race, with Republicans capturing the advantage over the past 20 years through a combination of technology, big data, expertise, and electoral strategy. The result has been a set of some of the most contentious—and legally challenged—racial and political gerrymanders in history. But despite the controversy, Republican strength has also increased, as target states where Republicans gained control of the mapmaking process in 2010 saw their share of legislative seats steadily grow, even as their actual vote shares decreased. In other words, these maps helped Republicans retain majorities even when they earned substantially fewer votes.

The states in Republicans’ crosshairs in 2010 were the ones that so often pop up in dozens of lawsuits about voting rights—Wisconsin, North Carolina, Pennsylvania, and Michigan—all crucial swing states in the 2016 election. All four states have also seen demographic shifts over the past 20 years that have increased their importance. Via the well-known REDMAP project, Republicans spent millions in legislative and governors’ races in those states, resulting in huge Republican gains, and also in Republican control over the 2011 redistricting process, which in turn engendered more Republican gains.

While not one of the core successes of REDMAP, Virginia was always a priority in long-term strategy. For one, the architect of REDMAP was Ed Gillespie, the former Republican State Leadership Council leader whom Northam beat yesterday. But Virginia has also been a key proof-of-concept for gerrymandering.

A purpling state with distinct geographic patterns of movement and a burgeoning population, Virginia would be an ideal state for showcasing some of the recent extreme trends in redistricting: packing reams of Democratic voters in Northern Virginia and the Tidewater into a select few districts, and then picking off influential D.C. suburbs and college towns across the state and diluting Democratic votes by placing them in heavily-red districts. And, in the case of Virginia, with well-known settlement patterns, such a map might be drawn purely on partisanship lines instead of using race, a factor in political mapmaking that has recently attracted the ire of courts.

That Virginia didn’t succumb to such a political mapmaking is in part because of the failure of either party to capture majorities in the General Assembly and the governor’s house at the same time. In Virginia, like in many states, the governor has veto power over maps passed by the state legislature, a dynamic that makes compromise necessary if Democrats and Republicans split control of the two branches.

“Democrats were in charge in the [Virginia] Senate, and Republicans were in charge in the House of Delegates,” says Brian Cannon, the director of the nonpartisan redistricting reform group One Virginia 2021. “We ended up getting a bipartisan gerrymander.”

The scheme created by Democrats and Republicans in 2011 that Cannon mentions was a strange one: Yes, it created unnatural districts using tactics that might be considered gerrymandering in any light, but those tactics were used to preserve incumbency and the current balance of power in the statehouse.

With Republicans running the same playbook in REDMAP 2020, and Democrats countering with a well-funded redistricting scheme of their own, the National Democratic Redistricting Committee (NDRC), the 2017 Virginia election was both the first and one of the most important battlegrounds between the two efforts. According to Kelly Ward, the executive director of the NDRC, “a good portion of the Democratic disadvantage in Congress boils down to seven states,” many of which have seats and governorships on the table in 2018. “You have Ohio, Michigan, Wisconsin, Florida, Virginia, and Pennsylvania,” Ward says. “If Democrats can win those seats, then we have a seat at the table during the redistricting process.”

What Ward’s group needed to block a power play by Republicans in Virginia was a win in the governor’s mansion or at least a stalemate in the statehouse. She might’ve gotten both and more. Northam’s single term will take him through the redistricting cycle. With somewhere between 15 and 19 seats flipped in the state legislature (pending recounts), Democrats might even control the House of Delegates for now, while Republicans still hold a slim advantage in the state Senate. But the real test again comes in 2019, when all of the seats in both the House of Delegates and the Senate will be up for grabs in a final round of jockeying for mapmaking.

With hard fights ahead in 2018 and 2020 in places like Texas, Georgia, and Florida, an uphill climb to gain even veto or compromise power in North Carolina, Michigan, Wisconsin, and Pennsylvania, and one more big push in Virginia, Democrats and opponents of 2010’s extreme gerrymanders will take the wins as they can.