Gerrymandering—the process of drawing congressional districts within a given state to deliberately advantage one party or another—distorts the will of the voters and has significant consequences for policy making. It helps entrench incumbents, makes life more difficult for third parties, and often gives an edge to candidates at the extremes of the political spectrum.

Libertarians, and others outside the red-blue binary, should want to reduce gerrymandering as much as possible, in the interest of creating a somewhat level playing field for future elections. As I write in this month's print edition of Reason, it's probably not possible to fully remove partisan influence from congressional map-making, but mapping technology and district-drawing algorithms can help limit some of the worst abuses on both sides. To the extent that those solutions can be implemented at the state level, they should be welcomed and encouraged.

But we should be careful, I think, about overstating the extent that gerrymandering is responsible for macro-level outcomes like control of the U.S. House of Representatives. Gerrymandering can have significant influence on the outcome of individual congressional races—and for that reason alone deserves attention—but gerrymandered districts (or the lack thereof) did not singlehandedly swing Republicans into power during the 2010s. And if the GOP is bounced from control of the House this November, gerrymandering will not be the reason why.

That's not what partisans on either side want you to think. No one less significant than former President Barack Obama has blamed Democratic losses during his admininstration on "sharply gerrymandered districts that are very safely Republican." Eric Holder, Obama's attorney general, is now heading a campaign organization aimed at helping Democrats retake state legislative seats before the 2021 reapportionment happens.

On the right, Rep. Ryan Costello (R-Penn.) announced this week that he would not run for reelection, a decision that has been widely attributed to the fact that his district—one of the most highly gerrymandered in the state, until it was recently redrawn by the Pennsylvania Supreme Court—now tilts towards Democrats.

Summing all this up, The Week's Damon Linker, a former conservative, says Republicans "decided to embrace flagrant cheating" in the last redistricting cycle to ensure a House majority via gerrymandering. Take Pennsylvania, he writes, where Republicans lost the statewide cumulative vote in the 2016 House elections but ended up winning 13 of the 18 districts. Remove that unfair advantage, Linker concludes, and Republicans would rightfully become a minority party.

It's certainly true that gerrymandering helped to shore up Republican majorities in Congress during the Obama years, but un-gerrymandering is not going to be the thing that costs the GOP it's control of the House. To understand why, look at this analysis from The Cook Political Report. It compares the Republican-drawn districts used in Pennsylvania for the 2012, 2014, and 2016 cycles with the new districts drawn by the state Supreme Court for the 2018 cycle.

I've recreated the The Cook Political Report's chart below, to better illustrate the point:

Most observers agree that the new map tilts towards Democrats in subtle ways (more on that here), but overall it's a more fair product than the map it replaced.

You'll notice that Republicans are still favored to win 11 of the 18 districts, based on registration alone. That's despite the fact that Pennsylvania has about 900,000 more registered Democrats than registered Republicans. The reason? Pennsylvania, like America as a whole, is a natural Republican gerrymander—by which I mean that Democrats tend to be clustered closely together and Republicans spread out over larger areas. The GOP has a natural advantage, given the current ideological and geographical bent of the two major parties, even without any creative district-drawing.

What does this mean for November? In a year with no generic advantage for one party or the other—like in 2016, when the GOP lost the statewide cumulative vote by a narrow margin—Pennsylvania's new congressional map might cost Republicans one or two seats, depending on how the votes were distributed. Going from a 13–5 edge (which the GOP had before the special election in the 18th district earlier this month) to a 11–7 edge would be a disappointment for Republicans, but hardly enough to doom the GOP's chance of controlling Congress, as Linker predicts.

What would doom Republicans, though, would be an election cycle where Democrats had an overall five-point advantage. On the new map, that would be enough to give Democrats 10 of the state's 18 seats. A result like the one in the special election earlier this month, where Connor Lamb overcame an R+11 registration edge to win in the old 18th district, would be catastrophic for the Pennsylvania GOP.

But if that happens, it won't be because new lines were drawn. A D+11 wave would have swamped the GOP even under the old map.

If Republicans get crushed in November in Pennsylvania (and elsewhere), it won't be because of redistricting. It will be because they tied themselves to an unpopular president, because Republicans are less likely to vote for a party that abandoned promises to downsize government, and because Democrats are increasingly energized to vote the GOP out. And it will be because voters of all stripes are still angry at the status quo—and for now at least, Republicans are the status quo.

Whatever its effects, redistricting reform is a worthwhile project for both parties to pursue before the next round of map-making occurs in 2021.

If and when Democrats "breach the barriers erected by the GOP in Congress and key states," Linker writes, "liberals and progressives can begin to dismantle these institutional obstacles to majority rule." He believes Democrats will be "unlikely to enact in-kind countermajoritarian hurdles against Republicans," and will be happy to have merely "a fair chance to compete."

I'm skeptical about that too. Democrats—given the chance—would likely attempt to enact favorable gerrymanders in Pennsylvania and North Carolina, just as they've already done in places like Maryland and Illinois. I hope Linker is right, but in the event that he's wrong, citizens should push politicians of both parties to mutually disarm the congressional gerrymandering threat.