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Texas is sooooooooo gerrymandered…

How gerrymandered are we? By this measure, we’re literally as gerrymandered as we could possibly be.

But just how biased have modern-day maps become in the state of Texas? The map that was approved last October is so highly biased, it is quite literally off the charts, according to the SMU findings.

The open-source software that the SMU researchers use helps them generate millions of maps that follow state guidelines for drawing districts.

The software allowed the researchers to answer a simple question: “If you didn’t try to design [maps] to maximize Democratic seats or Republican seats, if you just pick them randomly to satisfy the law — what would you get?” said Andrea Barreiro, associate professor of mathematics at SMU.

Using this large set of randomly generated maps, the group established a baseline for what a typical map that follows state guidelines looks like. With this baseline, the researchers were then able to measure how far from the baseline a proposed map was — and, therefore, how biased it was.

“If you have something that’s way outside of [the baseline], then there must have been some design goal that pushed it away from all these randomly generated maps, and that’s what we would call a biased map,” said Scott Norris, SMU associate professor of mathematics.

As soon as Texas’ first proposed congressional maps were made available on the Capitol Data Portal in late September, the SMU team got to work analyzing how the maps fared.

As different maps were proposed, the team generated over a million maps to create an unbiased baseline, offering key measures that are commonly used by political scientists to assess gerrymandering.

They completed this analysis for 59 proposed congressional maps. (The SMU team also shared their analysis for proposed Texas House, Senate and city council maps.)

Of the 1.5 million maps that the team generated and analyzed to compare with the final proposed Texas congressional district map, not a single baseline map showed levels of bias as high.

The proposed map was more biased than every single map their software had generated, the SMU researchers showed.

With their findings in hand, the SMU team reached out to all members of the Texas subcommittees involved in redistricting, as well as the researchers’ own local legislators.

They sent emails and posted to the comment portals provided by the legislature. Several of them testified at an open community hearing, explaining how this software works and advocating for its use to create less biased maps.

But they only heard back from a few offices. “The only people that we have actually spoken to are Democrats. … As you might expect, we haven’t had any interest from Republican members of the committees and, you know, that makes sense from their perspective,” said Norris.


The SMU group’s software revealed that the approved Texas map reduced the competitiveness of almost 50% of congressional districts in the state. This means that Republicans can win 50% of the state’s congressional seats, with only 42.2% of the state’s votes, the researchers showed.

In addition to dampening the need for officials to earn votes, gerrymandering can also leave large numbers of voters in a district with a representative who is out of touch with their community, said SMU researchers.

“When we testified to the House about this, I was struck [by] how many rural Republican voters were basically pleading with legislators not to break up their districts,” said Matthew Lockard, SMU associate professor of philosophy.

Farmers worried that their lives are so different from those of the city voters they might be in a district with that it just didn’t make sense.

You can see all the data here. I will confess, I don’t really understand the numbers they have in the tables there, but you don’t need a deep understanding of their methods to grok that the Republican-drawn ones were more gerrymandered than all 1.5 million randomly-drawn legal maps done by the team. We saw last decade that in a rapidly growing and diversifying state like Texas big changes can happen in a short time. That doesn’t mean it’ll happen again, just that the future isn’t set in stone. But that’s not for lack of trying on the Republicans’ part.

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  1. Mainstream says:

    I would be interested in their findings if they evaluated the 1990 maps drawn by a Democrat legislature.

  2. Ross says:

    Here’s a State website with redistricting history, for those interested in seeing how districts have changed over the years

  3. Joel says:

    Mainstream: imagine my surprise that the first comment here was you, both-sidesing (and also intentionally mis-naming the Democratic party, which is totally something a moderate does).

    You know what – I bet you’re right that those Democrats did gerrymander. And I would also love to see that analysis, though primarily because I expect it would make the larger point that this time is not business-as-usual levels. Or do you seriously think the 1990 Democratic gerrymander would be worse than of 1.5 million randomly generated maps?

  4. Mainstream says:

    Joel, yes. CD18 and CD 29 in the 1990 map are crazier than anything that has ever come afterwards in the history of Texas.

  5. Souperman says:

    The fajita strips of the 2003 Congressional map from Travis County all the way to the Mexican border (and the confluence of three Congressional districts in Austin designed to replace all representation of Travis County with a Valley Democrat, a Houston Repub, and a San Antonio Repub; they just didn’t manage to oust Lloyd Doggett and Michael McCaul won instead of a Houston Repub), as well as the Killeen Doughnut of the 2021 State House map would disagree. I did look and yes, those two 1991 districts were a bit jagged, but definitely more compact than many current districts.

    I worked it out for the 2020 election and I literally had 10 members of the US House closer to my house than my “representative” in the 2013 map (the aforementioned Michael McCaul, who lives west of Downtown Austin; I live south of Tomball), and I was being charitable (if I didn’t know where a Rep lived, I placed them in the far end of their district from me).

    But where we do seem to agree is that judicial oversight is vital; the 18th and 29th from 1991 were ruled unconstitutional, as were 5 districts from the 2003 map. The new and worse Roberts court seems even less inclined to step into unfair maps than before.

    I would be interested in the analysis as well, but the both-sides-do-it argument is kinda weak when we’re looking at something in a different world with far worse computers. Texas has gained 12 million people since the 1990 Census and I was 8 years old in 1991, so I imagine demographics may have changed a bit, as well. Rick Perry was less than a couple years removed from being a Democrat himself at that point.