Old and new

 I'll start with the new.  The SAVE Act requires proof of citizenship in order to register to vote.  If it were implemented, which party would it help?  The most convenient form of proof is a passport--of course, people who don't have a passport could assemble the necessary documentation, but it's safe to say that many of them would not get around to doing it.   There aren't many surveys that include questions about both passports and politics, but Pew had one in February 2016.  52.5% of Democrats and 46% of Republicans said they had a passport; independents were in between at 48%.  The survey didn't have any questions about anticipated vote in November, but it did ask who they wanted to get their party's nomination.  Among Republicans who had a passport, John Kasich led with 33%, followed by Ted Cruz with 23% and Donald Trump with 20% (the rest were undecided or scattered among other candidates).  Among Republicans without a passport, Trump led with 31%, then Cruz with 25%, and Kasich third with 20%.  The difference by passport status was smaller but still apparent after controlling for education.   That is, if this pattern held today, it's not just Republicans that would be more affected, but especially Trump's base.  I think the pattern would hold, because distrust of foreign countries is a central part of Trump's worldview, and people who distrust foreign countries are less likely to be interested in getting a passport.  

And now, following up on two older posts:

1.  In Munich, Alexandria Ocasio-Cortez said that high levels of inequality were to blame for the growing strength of authoritarian movements.  In December, I had a post about a paper by Eli Rau and Susan Stokes which found that income inequality was associated with a higher risk of "democratic erosion."  I found that this was still the case after controlling for another potential influence, presidential vs. parliamentary system.  Rau and Stokes noted that "democratic erosion" was becoming more common, and suggested that inequality could explain this trend:  they spoke of "the suspicion that rising inequality is playing a role in the wave of cases of democratic erosion."  However, they didn't directly look at changes in inequality.  This is the average of their measure of inequality by year (adjusting for changes in the nations in the sample):

It peaked around 2005, and in 2020 was lower than it had been in 1995.  Although nations with higher inequality seem to have higher risk of democratic erosion, inequality is not behind the rise in democratic erosion.

2.  My most recent post was about the difference between two presidential ratings:  one by political scientists, the other by a collection of conservative journalists, activists, and academics.  I compared ratings by the conservative (PragerU) sample to Republicans in the political science (APSA) sample and concluded that the differences weren't entirely due to ideology.  It occurred to me that I could improve the analysis by considering party differences in the APSA sample.  That is, maybe rankings depend on ideology and the PragerU sample was farther to the right than the APSA Republicans were.  You can estimate a model where the rating of each president by each group is the product of scores for the president and the sample.  If you do this, the difference between PragerU and the APSA Republicans is about 1.5 times as large as the difference between APSA Republicans and Democrats.  If you fit this model, the largest residuals (by absolute value) are for McKinley, Kennedy, GW Bush, Polk, Taft, and Madison.  McKinley, Bush, Taft and Madison get relatively better ratings from APSA Republicans, and Kennedy and Madison get relatively better ratings from PragerU.  For most presidents, the APSA Republican ratings are in between the APSA Democrats and PragerU; for these six, the PragerU ratings are in between the two APSA groups.  For example, LBJ got 74 from APSA Democrats, 55 from APSA Republicans, and 35 from PragerU; JFK got 66, 50, and 57.

In a general way, my conclusion that there was something beyond politics holds up, but my focus on Wilson and Coolidge was misplaced.  Basically, there's a big ideological/partisan difference in the rating of these presidents, which shows up within the APSA sample and between the APSA Republicans and PragerU.  As far as what that "something" is, I would say it reflects differences in knowledge.  For example, I gather that most experts regard Polk as an effective president, although there's disagreement about the merits of his policies (Republicans tend to be more favorable).  APSA Republicans would know that, while for many in the PragerU sample, he would just be another one of the nondescript run of presidents who came in between Jackson and Lincoln.   In my last post, I also said that the PragerU sample gave higher ratings to pre-1900 presidents; there's still some evidence for that, although it's weaker than in my previous analysis.

[Some data from the Roper Center for Public Opinion Research]