In my new article on Persuasion, I try to explain as clearly as possible how to think about the political effects of demographic change and get beyond the standard naive interpretation of these effects. It's not that complicated if you keep an open mind and think logically about that attendant possibilities.
"Rising racial diversity is an ongoing trend in the United States, as the latest Census Bureau data confirms. In fact, the figures suggest that over the past decade, the white population will have declined for the first time in the nation’s history.
This demographic change is generally understood to be beneficial to the Democrats’ electoral fortunes, as John Judis and I argued in our 2002 book, The Emerging Democratic Majority. That’s a reasonable viewpoint based on a very simple idea: If voter groups favorable to the Democrats (racial minorities) are growing while unfavorable groups (whites) are declining, that should be good news for the Democrats. This is called a “mix effect”: a change in electoral margins attributable to the changing mix of voters.
These mix effects are what people typically have in mind when they think of the pro-Democratic effects of rising diversity. But mix effects, by definition, assume no shifts in voter preference: They are an all-else-equal concept, as we were careful to stress two decades ago. If voter preferences remain the same, then mix effects mean that the Democrats will come out ahead. That is a mathematical fact.
But voter preferences do not generally remain the same. Therein lies the reason why, in some cases, rising diversity has not produced the dividends for Democrats that many activists and advocates anticipated—and, in other cases, has little to do with gains that Democrats do make....
[D]emographics set the playing field, but they are not destiny unless all else remains equal. And all else almost never remains equal. Therein lies a challenge for the Democrats that the simple fact of rising racial diversity cannot solve.