Very cool! Varying coefficient models directly applicable to ecological inference - should try this out in a many-covariate setting soon

This is also not quite true. Empirically, states with independent commissions or nonpartisan drawers produce maps that are at or near the median simulation on partisan + racial demographics. Because of that, it's reasonable to treat the median as a forecast for a drawer following only certain rules

This is not accurate! Just like polling, we can randomly sample maps in a representative way, and understand typical maps without looking at every one. We have mathematical proofs that these algorithms produce representative samples if run long enough.

Unfortunately some inaccurate info in this thread. The point of the NYT sims was to see what typical maps drawn without the VRA would look like. But the maps Stephen draws incorporate VRA compliance. Also wrong info on the algorithms which I will say more about separately

Not enough news coverage of how the insurrectionist reparations fund is a clear violation of the 14th Amendment. We need to enforce the Constitution in its original meaning and plain text. You can't imagine away parts of the Constitution just because it is politically inconvenient.

Our ALARM simulations and redistricting algorithm at work! Back in 2022 we released all the code to generate nationwide simulated maps exactly so that people could explore hypotheticals like this!

Our simulations show that the act isn’t needed for minority representation in the South, if partisan gerrymandering were checked. www.nytimes.com/2026/05/17/u...

The number of conservatives calling the compact Memphis-based TN-09 an "illegal racial gerrymander" has been insane. Whatever Alito wrote, the loud and clear signal was that even if Black people make up a majority of a coherent community, they aren't allowed to vote for their representation.

SCOTUS invoked the Purcell Principle, which is that courts shouldn't make changes that affect an election too close to an election, to block a decision that would have required Texas to change its maps *last December* but now since it advantages Rs it's fine to change maps after voting has started

“Just do in person” is absolutely going to be a substantial part of the answer, but it is sort of annoying the “just do bluebooks, so simple” thing wrt AI and teaching. like it’s a *lot* more complex than that. a lot of shit the modern classroom relies on will have to totally revamped.

It is mind boggling how messy and low quality so much data is. Companies whose entire job is to provide data will turn in shit that barely works.

Purcell Principle Calvinball.

The Bonica-Grumbach take is that electoral politics is volatile, uncertain, and doesn’t map well onto the left-right spectrum. What we’re more confident about are sincere, costly anti-corruptionism antiwar courtpackin & scotus term limits VRA & gerrymander ban pro act & card check dc & pr statehood

A month later, here is what happened to this work. blog.thecoatlessprofessor.com/posts/extrac... #rstats

University presidents have lost the plot. Try this: “The Faculty Senate Chair does not speak for the University. He gave his own views as he is not only entitled but encouraged to do even at official University events.” Why would any one person’s views represent the diversity of views at UMich?

New updates to our WP from Sept, including new validation of precinct-level conf intervals & a nonparametric test of the identifying assumptions (!). 'seine' software now supports these 'local' estimates + partial ID bounds + the new test!

Identification and Semiparametric Estimation of Conditional Means from Aggregate Data https://arxiv.org/pdf/2509.20194 Ecological inference is the challenge of estimating subgroup behavior using only aggregate data like geographic averages. This paper introduces a new semiparametric method 1/3

Wrote a piece for @slate.com on how our theories of partisan polarization gave the SCOTUS majority more intellectual cover to kill the VRA slate.com/news-and-pol...

New working paper on the California Fast-Food minimum wage (will come out as NBER WP soon but posting now). Big increase in wages. Big drop in separations. Little change in jobs. (Bonus: sheds light on QWI vs QCEW measurement of jobs.)

Still thinking about these instructions In the South, minority voters express “different” preferences over candidates by being Democrats and voting for Democrats (see work by Ansolabehere) If you control for party, you control away the biggest outcome of those different preferences

The decision in Louisiana v. Callais claims, "By 2004, the racial gap in voter registration and turnout had largely disappeared.... Black voters now participate in elections at similar rates as the rest of the electorate" (26–27). This is misleading: White turnout remains much higher than non-White.

Also: What a sad vision of democracy. These people think that race is only ever used instrumentally. They do not think people have the capacity to really care about access and representation above-and-beyond accruing power. They think everyone is as cynical as they are.

Everyone should be prepared for the current Supreme Court to strike down proportional representation bills (at the state or federal levels) and the John Lewis Voting Rights Act with bans on partisan gerrymandering and new pre-clearance. You need a Supreme Court management strategy too.

This:is 💯 correct. The vast majority of Section 2 litigation (and settlements made under the threat of litigation) have been at the local level. Callais will gut minority representation in city councils, county supervisors, and school boards across the county.

Given the argument that ended the VRA, I think it’s time liberals did some self reflection about the now decades long obsession with partisan polarization as the problem, as opposed to authoritarianism, extremism, oligarchy, and racism

The answer is proportional representation. Proportional representation enables equal representation to minority voters as a structural feature, not as a litigated favor any future court can take away.

It is now time to rethink the single-member district that makes racial gerrymandering possible now. We need a solution that does not rely on the Court.

The Court came for Section 2 of the Voting Rights Act today. The Callais decision renders Section 2 "all but a dead letter," in the words of Justice Elena Kagan. Plaintiffs now have to prove intentional discrimination. This is almost impossible.

I don't think much remains to be seen... hard to see how any Sec 2 districting suit could be successful (i.e., remedy dilution) if the state can insist on whatever partisan outcome it wants

The Supreme Court is essentially constrained only by: 1) a norm that they follow precedent (this isn't written down anywhere, it is merely a norm), and 2) Congressional authority over their jurisdiction, funding, and composition. The second has been entirely abandoned, the first is on life support.

The NYT calls it a 'blow' to the VRA, but Thomas and Gorsuch are clear on what the effects of the decision will be: "an end" to the "misadventure" of "roughly proportional representation" for minority groups.

The egregious decision in Rucho now lets SCOTUS punch a massive loophole for VRA §2: partisan goals can justify disparate racial impacts. This is about districting, but the same logic would let states resurrect literacy tests, etc. as long as the stated goal was partisan discrimination.

This is correct. There is no future of democratic self government in the US with an unreformed Supreme Court. The Court is riddled with corruption and abuses of power and rooting out that corruption is a sine qua non of civic democracy in the United States.

This is perhaps the most significant Supreme Court race-related decision in modern history. While people will focus on Congress, this decision will dismantle thousands of districts electing representatives of minority communities at the state and local levels

Time to plug my simple congressional model again, which I've updated with the new VA plan: tinyurl.com/cmchousemodel. Net effect of re-redistricting is D+1.5 seats in tied environment, growing to D+2 seats in a D+10 environment. Bit more competitive map, too.

Have had the same reaction in the last year. Case in point: juries have performed so much better than other institutions!

I mostly agree with the larger point, I think: political effects of economic conditions are mediated through the media (writ large), which may not always reflect actual conditions. But tbc you can estimate the causal effect of X on Y and see if it is big or ~0! Don't let NHST tell you otherwise!

New WP! Philip O'Sullivan, Kosuke Imai, and I generalize an earlier SMC sampler for redistricting plans, allowing it to scale better & be applied to multi-member districts, too, like the Dáil Éireann (Irish parliament) below. Look for a new 'redist' version soon(ish)! arxiv.org/abs/2603.22188

Atrocity upon atrocity. Every detail here is worse than the last. www.theguardian.com/world/2026/m...

Strength In Numbers is looking for a smart part-time survey research assistant (or a few) www.gelliottmorris.com/p/strength-i...

LA City Council’s City President Marqueece Harris-Dawson says he has been pulled over four times while a member of the council; the most recent was this week. He missed a committee meeting because of the stop, according to him. Among the questions: “how do you have this vehicle,” according to him.

I just cannot underscore enough how uselessly simplistic this WAR-based mode of thinking about elections is. And it’s not even accurate! In Jain’s own construction WAR explains 25% of future residual candidate performance, including fundraising, candidate skill, district fit, & general vibes-y stuff

v0.2 of `bases` is up on CRAN! `bases` brings nonparametrics into your favorite modeling functions—using random Fourier features is as easy as sticking `b_rff()` into your formula. v0.2 brings graph Fourier & random convolutional features, `mgcv` integration, & more! corymccartan.com/bases/

I'd very much like to return to a world where academia, the sciences, the media, etc. *can* be neutral because everyone accepts their right to flourish, but that's not the reality we're living in.

The entire Democratic strategy debate — "moderate" or move left? fight or compromise? — is based on a misreading of data. Voters don't think Dems are too progressive; they think Dems are weak. The actual math on what to do about this isn't even close! New: www.gelliottmorris.com/p/new-poll-d...

Redistricting Reforms Reduce Gerrymandering by Constraining Partisan Actors is now forthcoming in the APSR! We use a game theoretic treatment and continuous DiD(iD) to show when redistricting reforms work with @corymccartan.com, @simko.bsky.social, Emma Ebowe, Michael Zhao, and Kosuke Imai

Specifically, the “issue” is/was my (non-)compliance with Regulation 9.016. A similar presentation I gave in Finland in October was also flagged for violating this same regulation because I had “transgender” in the title there too. www.flbog.edu/wp-content/u...

We need more people to know about this simple solution to gerrymandering ⬇️ Here's how proportional representation could make map manipulation impossible, and it’s actually achievable. Watch and share to spread the word: https://youtu.be/xN5V0au9Xms

finally: to the extent that it's possible safety isn't found in secrecy, it's found in numbers, and the former is at odds with achieving the latter.