It’s no secret that the Democratic majority in the U.S. House is already tiny. With next year’s midterm elections looming, Republicans realize they already have 212 seats, and the odds of them reaching 218 seats are in their favor.

Historical models aren’t doing Democrats any favors — the president’s party nearly always loses a lot of seats in the first midterm cycle — but just as important right now is the post-census redistricting process and the prospect of dramatic GOP gerrymandering. The New York Times reported last week:

Republicans hold total control of redistricting in 18 states, including Florida, North Carolina and Texas, which are growing in population and expected to gain seats after the 2020 census is tabulated. Some election experts believe the G.O.P. could retake the House in 2022 based solely on gains from newly drawn districts.

That last point is of particular interest: even if the American electorate doesn’t shift at all in terms of ideology or partisan preferences, Republicans would be well positioned to reclaim the House majority simply be redrawing the lines in their favor. The challenge for Dems is daunting.

There is, however, an obvious follow-up question: what about Democratic-led states? If Republicans intend to exploit gerrymandering for partisan advantage, why can’t Dems do the same thing?

The answer is … a little complicated.

Broadly speaking, there are three angles to this that are worth keeping in mind. Right off the bat, part of the problem for Democrats is that there just aren’t that many solidly blue states in which the party controls the governor’s office and the state legislature. What’s more, in some of these solidly blue states — see Connecticut, Hawaii, and Delaware, for example — there aren’t any Republican representatives with seats to take.

That said, there are notable exceptions that matter. In Maryland, for example, Democrats have a veto-proof legislative majority and an opportunity to create an all-Democratic congressional delegation. In New York, it’s possible Dems could draw a district map that could flip as many as five districts from “red” to “blue,” which would make an enormous impact on the national totals.

But I’m especially interested in the third group: states in which Democrats have effectively voluntarily surrendered their gerrymandering power in the interest of good governance.

In Colorado, for example, Democrats endorsed the creation of independent redistricting commissioners who’ll redraw the lines — instead of statewide elected officials in the increasingly “blue” state. One Democratic state lawmaker, who’d love to redraw the state’s map to benefit Democratic candidates but can’t, said last month, “We’re f***ing idiots.”

California, the nation’s largest “blue” state, also utilizes independent redistricting.

Unilateral disarmament stings. There are no examples of Republican-led states doing anything like this.

In New Mexico, meanwhile, there’s also a new advisory redistricting commission, though it’s within Democratic officials’ power to override its recommendations. The temptation will likely be strong: New Mexico Dems could create a map in which they have a clean sweep of each of the state’s three districts.

Of course, Congress could pass legislation to end partisan gerrymandering altogether. We’re waiting to see whether a handful of Democrats — Sen. Joe Manchin (D-W.Va.), I’m looking in your direction — allows a vote on such a bill.