Nate Cohn

Nate Cohn @Nate_Cohn

@mattrph23 oh-13 and oh-1 are both biden CDs — PolitiTweet.org

Nate Cohn @Nate_Cohn

40% of Ohio's population lives in Biden counties, and 36% live in Biden precincts. That would yield 5 or 6 Biden CDs, which is about what I get when I draw a map by nonpartisan standards. Current map is 4, though barely https://t.co/heN9fhsPEK — PolitiTweet.org

Nate Cohn @Nate_Cohn

40% of Ohio's population lives in Biden counties, and 36% live in Biden precincts. That would yield 5 or 6 Biden CDs, which is about what I get when I draw a map by nonpartisan standards https://t.co/heN9fhsPEK — PolitiTweet.org

Nate Cohn @Nate_Cohn

Counties may seem arbitrary, but jursidictional lines are one of the key criteria for nonpartisan map making. There are jurisdictions that obviously deserve a Democratic CD in other states that don't get one (Cobb, Ft. Worth TX, etc.). There's nothing quite like that here — PolitiTweet.org

Nate Cohn @Nate_Cohn

Well, 94% of votes in California live in counties that voted for Biden. There just aren't many areas that obviously entitled to a CD at the county-level (kern, NoCal, east of Sacramento and to its south). And they all got CDs https://t.co/bHqvRqhkOL — PolitiTweet.org

Nate Cohn @Nate_Cohn

We can look at it in terms of counties, too. Counties are a key building block for districts, and it captures something that precincts don't get: whether the precincts are grouped together in a way that lend themselves to effcient/inefficient districting — PolitiTweet.org

Nate Cohn @Nate_Cohn

In the case of California, the 84% share of votes cast in Biden precincts happens to exactly line up with the... 84.6% of districts on the new map that Biden won. Doesn't prove it's not a gerrymander, but it's a reason I don't think the proportionality argument is compelling — PolitiTweet.org

Nate Cohn @Nate_Cohn

The same measure, btw, shows some of the challenges Democrats have in other states. Only 44% of votes in Wisconsin were cast in Biden precincts! That's a huge part of their 'geography' problem, and why even a Dem draw would struggle to get to a 4-4 split — PolitiTweet.org

Nate Cohn @Nate_Cohn

What's the number for California? Well in 2020, 84% of votes were cast in Democratic precincts, even though Democrats won 64% of the vote (i'd guess the disparity is even greater using *people* not votes) That means we expect Democrats to win a disproportionate number of seats. — PolitiTweet.org

Nate Cohn @Nate_Cohn

You can imagine two states, for ex: one where Dems win 60/40 in every precinct (here we'd expect Dems to get all CDs), and one where Dems win 100% in 60% of precincts, and GOP wins 100% in 40% of precincts (here we'd expect the GOP to get a lot of CDs!) — PolitiTweet.org

Nate Cohn @Nate_Cohn

We can measure this phenomenon in a pretty simple way: what percentage of people *live* in Democratic precincts? what percentage *live* in Democratic counties? That's slightly different than vote share, but it's the one that really informs this problem. — PolitiTweet.org

Nate Cohn @Nate_Cohn

Why? Districts represent geographic areas. In lopsided states, a party tends to nearly everywhere. To take extreme ex, imagine a state where Reps won 70/30... but there was no place where Dems won. There's no way you could draw 30% of dists for the Dems. (WY/WV is an IRL ex) — PolitiTweet.org

Nate Cohn @Nate_Cohn

Here's a common one: proportionality. Dems got 65% of the major party vote; they get 80% of seats. I understand that response, but in all seriousness: proportionality is a great criteria, especially in lopsided states. In fact, the GOP gets ~ fair share https://t.co/fJXCfqVobZ — PolitiTweet.org

Nate Cohn @Nate_Cohn

There are lots of angry people insisting that California is a gerrymander. They don't even feel the need to argue it, because they think it's so obvious. (i think it's obvious the other way) So before I explain my case, let me ask: why do you think California is a gerrymander? — PolitiTweet.org

Nate Cohn @Nate_Cohn

This is a state Biden won by 30. I'm not saying Republicans should be grateful that they get districts, but no one should have any illusions about what a real gerrymander would mean for the CA GOP — PolitiTweet.org

Nate Cohn @Nate_Cohn

For the handful of you complaining that the commission-drawn California map is a gerrymander https://t.co/xZvejuLFN5 — PolitiTweet.org

Nate Cohn @Nate_Cohn

IE: if Texas turns blue, the GOP is still going to have a two-to-one seat edge and this gerrymander will look incredible. But it's entirely possible the Dems do better in '22 in TX than they would have on the old map — PolitiTweet.org

Nate Cohn @Nate_Cohn

If, hypothetically, the Democrats make another big round of gains in the once red suburbs of Texas, IND, STL, etc., the value of GOP gerrymanders will soar. For now, it's the Democrats who might make slight gains — PolitiTweet.org

Nate Cohn @Nate_Cohn

The GOP, OTOH, has really sured itself up against a Dem wave. There are 15 more CDs where Trump won by at least 15! In practice, that's less about playing defense against a wave and more about playing defense against highly unfavorable trends in formerly red, GOP-held suburbs — PolitiTweet.org

Nate Cohn @Nate_Cohn

Across the 265 completed CDs, there are 5 more Biden CDs than before and there are also 4 more CDs where Dems would survive in a rout. — PolitiTweet.org

Nate Cohn @Nate_Cohn

Given the extremely high relationship between presidential and congressional vote in '20, the easiest way to see that, to my mind, is to look at two measures: the number of Biden CDs and the number of CDs that are left of, say, Virginia (a hypothetical wave) — PolitiTweet.org

Nate Cohn @Nate_Cohn

In a lot of cases, the Democrats fare a little better on the seat count when you're really careful to make sure you're not adding in expectations of a 2022 rout into the cost of redistricting. — PolitiTweet.org

Nate Cohn @Nate_Cohn

And on the other hand, Democrats might have been underdogs in both VA-2/7 on the old map in '22. By that forward looking measure, one could say the Democrats might be favored to gain a seat due to redistricting — PolitiTweet.org

Nate Cohn @Nate_Cohn

Take VA, for instance. Dave treats this as an R+1 shift, since Dems aren't favored to hold VA-2 (which is true). But they probably would have won VA-2 in 2020 (this is still a Biden CD). So I'm not sure I'd call this a loss due to redistricting https://t.co/gPJxcwzmKt — PolitiTweet.org

Nate Cohn @Nate_Cohn

I broadly agree with this, though I'd add one additional twist on how to think about redistricting by seat: whether we're comparing to the actual outcome in 2020 or a hypothetical expected outcome on the old map in 2022 https://t.co/xrOKQaTZX6 — PolitiTweet.org

Nate Cohn @Nate_Cohn

To my eye, it's an improvement for the GOP. CD-7 looks like it's Biden+7 (while CD-10 was Biden+9 before), so that's probably on net-a good trade for the GOP. — PolitiTweet.org

Nate Cohn @Nate_Cohn

Final Virginia map evolves a quite bit from the first special masters proposal, with CD-10 becoming more Democratic and CD-7 becoming more conservative. https://t.co/1FLnKuXVAV — PolitiTweet.org

Nate Cohn @Nate_Cohn

@cwarshaw the estimates for GOP seats might be, for ex, 3 pts above the line at all values of x; the estimates for Dem seats might be 3 pts below the line for all values of x. — PolitiTweet.org

Nate Cohn @Nate_Cohn

@cwarshaw and based on the chart, i don't think it's obvious that incumbency is the core problem. if it was, the disparity between presidential vote and House estimate wouldn't be linear and grow as x approaches 0,1 — PolitiTweet.org

Nate Cohn @Nate_Cohn

@cwarshaw i'm using the numbers on the main table for 'predicted vote share.' i think the issue would probably be helped a bit with incumbency, but it's a pretty serious problem if it doesn't model open seats well (esp if that's default)? — PolitiTweet.org