Gerrymandering is a leading issue in many state elections for 2020, but you rarely hear anything about Maine. That’s because this state solved the problem of excessively partisan gerrymandering a long time ago – yet its solution seems hardly to come to the notice of those working overtime on the problem.

Maine’s system was not without peculiarities. Until recently, the state reapportioned its congressional, legislative and county commission districts two years later than most states, even though the relevant U.S. Census numbers are known in plenty of time. Thus, new districts took effect for the 2004 elections, not 2002 – making existing districts unnecessarily outdated.

That changed when the Maine Republican Party took the state to court over congressional redistricting in 2011. Nationally, Republicans had managed a virtual takeover of many state houses a year earlier. Then, they used their majorities to gerrymander with a sweep and precision never before seen; that’s the problem many are trying to fix.

Maine Republicans did win a federal court decision requiring the state to move up congressional redistricting to 2012, but the legislative districts were, as usual, revamped for 2014. A subsequent constitutional amendment, ratified by voters, aligned the process so, starting in 2022, all districts will be done together.

Yet partisan attempts to gerrymander in Maine have generally failed, because of the genius of our system. There are two steps: First, redistricting plans proposed for the Senate and House have to pass by a two-thirds majority in each body.

If such a supermajority isn’t achieved, the apportionment is ordered by the Maine Supreme Judicial Court. Since it’s exceedingly rare that either party controls a chamber by two-thirds, this is an elegant check on extreme partisanship.

It also works better than the solution commonly advanced elsewhere: a nonpartisan commission, composed of citizens – or, in some case, judges – charged with drawing district lines “fairly.” In practice, however, fairness is more complex than just seeing that Democrats or Republicans don’t gain undue advantage.

Such commissions generally don’t understand politics – in fact, they’re chosen primarily because they don’t. Although we often assume that allowing lawmakers to draw their own districts is somehow suspect, it’s preferable to turning the job over to a bureaucracy.

After all, legislators know their constituents quite well, since in Maine they get an election report card every two years. They know which towns fit well together, politically, and which don’t; these are not trivial concerns.

Generally, if the parties don’t agree by two-thirds, the state supreme court looks at both plans – there are rarely any plans except from the parties – and makes a reasonable accommodation between them.

An exception came in 1994, when, shortly after the replacement of then-House Speaker John Martin, forced to step down after an unprecedented 19 years at the helm, the court got two plans – and accepted the House Republican plan, intact. Democrats gambled, and lost.

Whether or not resentment about Martin colored the court’s judgment, the resulting reapportionment was devastating for Democrats. No fewer than seven Democratic representatives were placed in districts already represented by Democrats, so the party effectively lost seven incumbents before the November campaigns even began.

Republicans nearly won a majority that year, picking up 14 seats. Chastened House Democrats remembered, and in 2004 negotiated a redistricting plan with House Republicans, while the Senate – as it often does – let the court decide.

Because the Maine system works so well, it causes little fuss, and thus gets little notice. But it’s clearly superior to attempting to take reapportionment – a vital political function – out of the political process.

Consider Election Day in even the smallest towns. The ballot clerks and poll watchers you say “hello” to are most often supplied by the Republican and Democratic parties; few nonpartisan volunteers want to bother, and so it’s the political parties themselves that help keep our elections fair.

Perhaps Maine’s system could next be adopted by neighboring New Hampshire. Gov. Chris Sununu, a Republican, just vetoed the nonpartisan commission bill a Democratic Legislature sent him.

If legislators there had instead proposed the Maine system, Sununu would have been hard-pressed to find a reason to veto it; if he had, his own party might have decided to override him.

It’s simply a better method – limiting, but not eliminating, partisan impulses – and represents a common-sense reform any state could adopt.