Thread by @Nate_Cohn

One theme in my replies yesterday is an assumption that plausible reforms under consideration--ending gerrymandering, DC/PR, HR1, etc.--would so fundamentally change the electoral incentives that the GOP would have no choice but to moderate
I don't think that's clear at all

That's not to say that they wouldn't make things tougher on the GOP, but in terms of the magnitude of the effect consider this: the GOP would probably still win all three branches of government in 2016, a fairly close election, if all of those changes were enacted

It's useful to go by chamber. Adding up to four Senate seats would certainly help Democrats, but it wouldn't be enough to flip control in any election this decade.
It would move the Senate bias from R+5 to R+4. Hardly a huge incentive to remake the GOP.

None of this has a real effect on the presidential race. Only adding Puerto Rico has any certain effect, it's only large enough to cancel out the net-6 ev swing that resulted from reapportionment.
In '16, it expands Clinton's lead in the popular vote without changing the outcome

One could assert, without really any serious evidence, that Clinton would have won with Democratic voting rules under HR1. Can't rule it out, I suppose, but I don't think it's a credible case (and one could just as easily argue Trump would do better)

Then there's the House. Here's where proposed reforms really can fix the GOP bias in the chamber. All you need is to mandate partisan fairness criteria.
And today the GOP has a 2.4 pt structural edge, that's poised to grow in 2022.

But of the three branches, the House is the one where there's the murkiest relationship between changing incentives and changing the character of the party.
Most Republicans will still be in safe districts, and there's no single national campaign for House like the presidency.

In the end, only the sliver of Republicans running in blue seats have an incentive to moderate. That certainly matters! But it won't redefine the GOP in their image; the overwhelming majority of House Republicans would still, say, back the Big Lie

In contrast, the presidency is the spot where it's easiest to moderate the GOP in response to electoral incentives, but it's the place where the Democratic proposals do the least

As a result, changing GOP electoral incentives requires a lot more than what's on the table. It probably starts with the Electoral College, whether it's NPV or proportional EC allocation. In the House, you probably need something like MMD + RCV, or even a multiparty system

The Senate, OTOH, doesn't even have a radical solution. Even adding DC/PR/VI/NMI/AS/GU would still leave the chamber with an R+3 Republican advantage v. the current popular vote.
You'd probably have to send it the way of the House of Lords, risking secession or civil war, etc.

But even then, just how much would GOP behavior really change? I just don't know. They don't seem very responsive to adverse shifts in places like CO, VA, AZ, GA, for instance.

If the GOP is a sectarian party, we wouldn't expect moderation; it only represents the sect.
A loss of electoral viability could just as easily turn it against democracy or continued coexistence altogether, and there's all kinds of conservative rhetoric to that effect

Finally, I'll end on a provocative note: it seems just as likely to me that a less biased electoral system would shift many Democrats to the left, mitigating the incentive for Republicans to moderate.

There are all kinds of plausible reasons why Democrats--or anyone--might support the proposed changes. I just don't think it's credible to argue the proposals in question will either moderate or defeat the GOP

https://twitter.com/PetePetersonJr/status/1398291867863764992?s=20