Democrats seemed not to believe that they would be allowed to strive for partisan balance in addressing Republican gerrymandering.
Few people expected that the Pennsylvania congressional map, which the state Supreme Court ordered redrawn to undo Republican gerrymandering, would prove to be as favorable to Democrats as the one adopted by the court on Monday.
Perhaps the easiest way to convey the cause for surprise: The new map is better for Democrats — by nearly every measure — than the maps that Democrats themselves proposed.
How could that be?
It is hard to explain. Perhaps all four Democratic map proposals reflected an earnest effort to reach a compromise with Republicans. The more likely explanation is that Democrats did not believe it was realistic to demand such a favorable map, since it would require a series of Democratic-leaning choices. And the court order did not specify that the maps should aim for partisan balance, which might have justified a more Democratic map.
Apparently, a more favorable map was quite realistic; after all, it is now a reality, one that gives a significant boost to Democratic hopes of retaking the House. It’s a reality because the newly adopted map consistently makes subtle choices that nudge districts in the direction of Democrats.
Many of those choices are easy to spot on a map. Every potentially competitive Republican-held district juts out to add Democratic areas, like adding York to the 10th District, Lansdale to the First District, Reading to the Sixth District, Stroudsburg to the Seventh District, South Philadelphia to the Fifth District, or Mount Lebanon and Penn Hills to the 17th.
There are also subtle choices that are harder to see. They’re less about picking and choosing municipalities and more about how to group counties. These choices also often work to the advantage of Democrats, like the decision to center the 12th District in Beaver rather than in Butler County, or to have the Fifth District, rather than the Fourth or the First, take population in Philadelphia.
Any of these decisions can be justified. It is also possible, although unlikely and unproven, that only this combination of choices yields the absolute minimum number of split counties or municipalities, the key criterion of the court order.
But in all of these cases, there were Republican-leaning alternatives of seemingly comparable merit. Collectively, it’s a pattern of augmenting Democratic strength, inching the statewide map closer to partisan parity.
This does not necessarily mean the map amounts to a “Democratic gerrymander,” as some have suggested. Over all, it admirably adheres to traditional nonpartisan redistricting criteria, like compactness and the avoidance of unnecessary county splits. But the map makes Democratic-tilting choices so consistently that it is hard not to wonder whether it was part of an intentional effort to achieve partisan balance in a state that is fairly evenly divided.
It would be somewhat surprising, at least to me, if the court drew this map without that goal in mind. Nathaniel Persily, the Stanford professor who helped draw the map, has been barred by the court from discussing it.
A series of pro-Democratic choices would be necessary to create statewide partisan balance, since lopsided winning margins in Philadelphia and Pittsburgh put Democrats at a considerable disadvantage in translating their votes to seats statewide. In fact, the new map still slightly advantages the Republicans with respect to the statewide popular vote.
Perhaps it shouldn’t be a surprise if the court strove for partisan symmetry in the context of a partisan gerrymandering case. But the court order did not say that the maps should strive for partisan balance, and it seems that’s the reason Democrats did not strive for it, either.
Michael McDonald, an associate professor at the University of Florida, suggests Democrats held back from greater ambition in part because they were protecting incumbents. But there was only one plausibly vulnerable Democratic incumbent to protect, Matt Cartwright, and there is little reason to believe the effort to protect him weakened the Democratic proposals.
Mr. Cartwright’s new district voted for President Trump by 10 points; in the Democratic proposals, the district voted for Mr. Trump by an average of nine points. Just as important, even a concerted effort to protect him would have little effect on the overall statewide map. It would be enough to flip the old 15th District from Mr. Trump to Hillary Clinton (going by 2016 results) but no more. And it wouldn’t flip the 15th District in the other contests where Democrats generally fared better, like the 2012 presidential election.
The map comes close to maximizing the number of Democratic opportunities while complying with the court’s order to minimize county, municipality or precinct splits except to make sure each district has about the same number of people. Perhaps the only plausible way to substantially improve Democratic chances from here would be to split the city of Pittsburgh, an unlikely choice given the requirement to avoid unnecessarily splitting municipalities.
Over all, it’s a huge lift to Democrats’ chances. In this political environment, they’d probably be favored to gain around four seats in the state, up from the two they were favored to carry before. They are overwhelming favorites to win the new versions of the old Seventh and modest favorites to win the old Sixth and 15th, with very good additional opportunities in the old Eighth and 12th, and two long-shot options in the old Third and Fourth.
Alone, the approximately two-seat shift toward the Democrats improves the party’s chance of reclaiming the House by around 5 percent, and even more if the race remains so competitive heading into Election Day. It further diminishes the already deteriorating Republican structural advantages — including incumbency and geography — that have long been the key to G. O. P. hopes of surviving a so-called wave election in the House.
At the beginning of the cycle, it was hard to identify more than a dozen national races where Democrats would have a 50-50 or better chance to win in a wave election. After this decision — and months of strong Democratic recruitment and a wave of Republican retirements — it’s a lot easier to come up with the two dozen seats they need to flip the House.
