You don't have to look far to find people diagnosing gerrymandering as the source of all of our nation’s woes, including (but surely not limited to) the shutdown. From this perspective, Republicans are gerrymandered into districts so conservative that the GOP is held hostage by ultraconservative primary electorates. Even President Obama has blamed the GOP "fever" on gerrymandering. These concerns are not totally misplaced. Gerrymandering is undemocratic, and it did help consolidate the GOP’s House majority in 2012. But, as I’ve written before, the significance of gerrymandering is exaggerated. Republicans are in safe districts for an incredibly simple reason: Most of the country just isn’t competitive. If safe districts are the source of GOP extremism, then gerrymandering is not the cause.

Take Texas, a famously gerrymandered state. If you want to create competitive districts, you don’t have many great options. Of the state’s 254 counties, 244 were won by either Obama or Romney by at least 10 points. That's not how it used to be: Back in 1996, 92 counties were within 10 points. Perhaps unsurprisingly, these non-competitive counties tend to be extremely Republican. A whopping 176 of Texas’ 254 counties voted for Romney by more than a 40 point margin (at least 70-30). 81 of those counties voted for Romney by at least 60 points (ie 80-20). So, even a fair map would create plenty of incredibly red, safe, ultraconservative districts.

As a result, it’s very difficult to draw competitive districts that retain geographic and demographic coherence. In fact, one would need to gerrymander Texas to make competitive districts, connecting heavily Democratic cities with large minority populations to the deeply conservative countryside. And even that strategy might be struck down under the Voting Rights Act, which protects minority-majority districts.

Even though gerrymandering isn't responsible for the prevalance of extremely Republican districts, it's possible that gerrymandering still increases the overall number of Republican districts, as critics allege (although probably not by enough to flip the House, thanks to spatial inefficiency). But the fact that gerrymandering boosted the total number of House Republicans does not mean that gerrymandering made the GOP more likely to support extreme positions or shutdown the government. In fact, partisan gerrymandering usually reduces the number of extremely red districts. Why? Because the point of partisan gerrymandering isn’t to try and maximize the number of safe districts. The goal is to maximize the number of districts that are merely safe enough by packing as many of your opponents' voters as you can into a small number of extremely partisan districts while safely distributing the rest throughout your own districts. In this way, gerrymandering may actually increase the number of moderate Republicans.

You can see this in Pennsylvania, where a highly successful Republican-led gerrymander has given the blue state’s congressional delegation a 13-5 Republican-tilt. One place where gerrymandering is most obvious is in the Philadelphia suburbs, which lean Democratic but are mainly represented by heavily gerrymandered Republican districts. In the current arrangement, Republicans packed many of the heavily Democratic inner suburbs into two Philadelphia-based districts and the 13th district, and then constructed snaking districts linking competitive suburbs with the more conservative countryside. But those additional Republican districts are still relatively moderate. And indeed, these GOP-leaning districts in the Philadelphia suburbs have elected some of the most moderate Republicans in the House, like Jim Gerlach, Michael Fitzpatrick, and Pat Meehan. All three support a clean CR. And most of the supporters of a clean CR hail from blue or purple states with Republican-led redistricting efforts.