Arnold’s worried that the U.S. is moving to one-party democracy. 

I completely agree with Arnold that one-party democracy is possible.  This is a central theme of my forthcoming article on Singaporean political economy, and over the past six months I’ve blogged quite a bit about this topic (see here, here, and here for starters). 

There is also some evidence that unified government is less libertarian than divided government (see here and here for starters).  I should add, though, that the effect is not huge, and Singapore is a striking counter-example.

Nevertheless, I disagree with Arnold’s claim that one-party democracy is likely to happen in the U.S.  He assures us that, “it is quite easy for a one-party government to emerge when there are
ethnic blocs and a large public sector relative to the private sector.”  I see little evidence that either ethnic blocs or a large public sector are key variables here.  Instead, it looks like the key variable is voter homogeneity, which is in turn a strongly negative function of population.  It’s easy to find a city – whether it’s New York or Singapore – where almost everyone supports the same party.  It’s much harder to get this level of homogeneity at a state level, much less a national level.

Suppose the growing Hispanic population really did become uniformly Democratic.  What would happen?  I predict that whites and Asians would respond by becoming less Democratic.  I also predict that as Hispanics’ vote share grew larger, divisions would emerge; the Hispanic bloc voting would not persist if Hispanics were half the population.

If you dismiss this as idle speculation, I’m happy to make a bet.  Here’s what I propose: Contrary to Arnold’s fears, I predict that Republicans will regain control of at least one branch of the federal government at some point between now and January 20, 2017 (two inaugurations from now).  So Arnold, how about a $100 bet at even odds?  If you don’t like those terms, make me a counter-offer.