Axios has a report on a data project that Election Law at Ohio State (ELOSU) is pursuing. The idea is to compare how competitive the House districts in a state are as a group versus the competitiveness of the state as whole (as in a Senate race). For a very simple initial look at this, ELOSU took the statewide margin between Biden and Trump in 2020 and compared it to the average margin between Biden and Trump in the state’s House districts. (The Biden and Trump percentages in each state and district are from Cook Political Report.)

ELOSU plans to study these numbers more closely, but a first glance at them shows a striking state-district competitiveness gap in some states but by no means all. For example, in Georgia the margin between Biden and Trump was 0.3, but the average margin between them in Georgia’s House districts was 30.5. There were similarly large gaps in other very competitive states, including Pennsylvania, North Carolina, and Wisconsin.

As the Axios report observes, this competitiveness gap isn’t necessarily the result of partisan gerrymandering (although it is necessarily the consequence of the requirement that House delegations be divided into single-member districts). The reason why House seats might be uncompetitive even in a super-competitive state could be the need to comply with the Voting Rights Act, or simply the “big sort” combined with a mapmaker’s desire to keep rural and urban counties intact. But it is also possible that a state’s House districts are more uncompetitive than necessary to comply with the VRA and to keep counties intact. If so, the extra uncompetitiveness of House districts may be the result of a mapmaker’s partisan motivation to gerrymander the districts to protect against the threat of a competitive challenge.

This analysis suggests the possibility of a straightforward method Congress could adopt to combat partisan gerrymanders. Congress could require states to justify any gap, or at least any large gap, between statewide competitiveness and the average competitiveness of a state’s House seats. If a state could show the need for the gap, in order to comply with the Voting Rights Act or satisfy other legitimate districting goals (like keeping counties intact), then the gap would be lawful. But if this State-Districts Competitiveness Gap (SDCG) can’t be justified by valid districting criteria, then a state could be required to produce a new map that would still achieve all of its valid goals and simultaneously reduce this SDCG. The state’s obligation to defend its map in this way could be administered either in the context of a preclearance-type system or through federal-court litigation authorized by Congress pursuant to its Article I, section 4 authority to legislate procedures for House elections.