This post first appeared at The Brennan Center blog.

Partisan gerrymandering has long been a scourge on the American political landscape — a problem that many observers think is only getting worse with the increasingly technologically sophisticated ways to micro-manipulate maps.

But a big win last week for reformers in the Florida Supreme Court shows that citizen-led efforts to fix gerrymandering have teeth and are starting to yield promising results.

As in many states, the job of redrawing district boundaries every 10 years in Florida is left to the state legislature. Although the US Constitution and the Voting Rights Act constrained the legislature’s ability to draw maps to disadvantage minority communities, neither provided effective protection against partisan manipulation. In fact, in Florida, as in a number of Southern states, politicians often successfully defended maps that they drew by saying that they were attempting to disadvantage members of the opposing political party rather than minorities. The Florida state constitution, likewise, contained no limitation on the use of the redistricting process to achieve partisan ends. Not surprisingly, Florida’s congressional districts were wildly gerrymandered.

All that changed in 2010 when a group of Florida voters — frustrated by federal courts’ seeming inability to come up with an enforceable standard for partisan gerrymandering — successfully collected enough signatures to put a proposition on the ballot to reform redistricting by amending the state constitution. Their amendment proposed for the first time explicit constitutional standards for the legislature to follow when redistricting, including a requirement that “[n]o apportionment plan or individual district shall be drawn with the intent to favor or disfavor a political party or incumbent.” The proposed amendment also required that districts, “where feasible, utilize existing political and geographical boundaries.” Despite broad opposition from much of Florida’s political class, the amendment passed with more than 62 percent of the vote, winning in nearly every part of the state.

A crucial test for the amendment came with the 2011 round of redistricting when a group of Florida voters challenged maps drawn by the legislature on the grounds that, despite the clear dictate of the amendment, legislators and political consultants had operated behind the scenes to draw maps favoring the legislature’s Republican majority. After a long court battle, the Florida Supreme Court recently agreed, ordering the legislature to redraw eight of the state’s 27 congressional districts in time for the 2016 election.

The Florida win comes on the heels of a US Supreme Court ruling just a week earlier in Arizona State Legislature v. Arizona Independent Redistricting Commission, which upheld citizens’ broad power to use ballot initiatives to enact redistricting and other electoral reforms, even in the face of opposition from self-interested political insiders. And like Florida’s amendment, many of those reforms are starting to bear fruit.

In California and Arizona, voters used ballot propositions to take mapdrawing power away from politicians entirely, giving it instead to an independent body. Although both commissions are still relatively new, much of the early data is promising. Prior to creation of California’s independent commission, Democrats and Republicans had engaged in a “bipartisan gerrymander” to protect incumbents. With technology at their disposal, they were so successful that in 459 elections, only one incumbent legislator or member of Congress lost his or her seat over a 10-year span. Just five percent of the state’s congressional seats, in fact, were even marginally competitive. And despite a growing Latino population, Latinos were effectively locked out of new opportunities for power.

By contrast, the first commission-drawn congressional map successfully increased the number of competitive congressional districts in the state from five percent to 18 percent, while increasing Latino representation. Commission-drawn maps in other states have engendered much less litigation than maps drawn by legislatures.

Buoyed by these results — and by the Supreme Court’s reaffirmation that voters have the power to experiment with ways to rein in redistricting abuses — reformers in Illinois, Michigan, Ohio and South Dakota are already considering ballot initiatives to follow in the footsteps of Arizona, California and Florida. In short, this could be a real reform moment — and a chance for American voters to take power in their own hands to finally end a problem that has dogged the country from its inception.