How much does Virginia's new, un-gerrymandered state House map help Democrats? A whole bunch
This fall, Virginia’s entire 100-member House of Delegates is up for election, and Democrats have a good chance to turn their 51-49 deficit into their first majority in 20 years. Importantly, this will be the first election held under a new court-ordered map that will be used in place of the previous GOP gerrymander, which federal judges struck down part of for discriminating against black voters.
There's still a chance that the Supreme Court could yet interfere, but with the candidate filing deadline now passed, that looks increasingly unlikely. So assuming the new map holds up, just how much better for Team Blue is this new map than the old one?
Under the old lines, which were last used in 2017, Hillary Clinton carried 51 of 100 seats, despite defeating Donald Trump statewide 50-45. Republicans represented three of those 51 Clinton seats, while Democrats held a lone Trump seat. Under the new map, by contrast, Clinton won 56 districts. Republicans now sit in seven seats Clinton won, while the one Trump seat occupied by a Democrat now would have gone for Clinton.
These statistics, however, are by no means the only way to measure how much the changes help Democrats. One way to look a little deeper is to sort each seat by Clinton’s margin of victory over Trump and see how the seat in the middle—known as the median seat—voted. Because Virginia has an even number of seats, we average the presidential margin for the middle two seats to come up with the median.
Under the old state House map, the median seat backed Clinton 48-46, about 3 points to the right of her statewide win. In other words, to win a majority under the prior lines, Democrats would have had to win either every single Clinton seat or some of the districts carried by Trump even though Clinton won the state, a sign of the GOP’s gerrymander. But under the new map, the median seat supported Clinton 50-45, which is identical to her statewide margin of victory and suggests the gerrymander's statewide impact has now been erased.
This hardly guarantees Old Dominion Democrats will win the majority, of course, especially given the cavalcade of misery surrounding Gov. Ralph Northam and Lt. Gov. Justin Fairfax, who’ve steadfastly refused to resign in the face of scandal despite widespread calls from fellow Democrats that they quit. However, these statistics do indicate that, should state House Democrats win more votes than Republicans across the state, they’ll stand a good chance of taking control of the chamber, unlike what happened in 2017.