Donald Trump's
recent attack on Judge Gonzalo Curiel's impartiality because of Curiel's Mexican ancestry brings to the fore the potential role immigrant populations might play in the upcoming presidential election. Potentially compounding Republican problems on this front, a recent Washington Post
article describes a substantial uptick in citizenship applications in the first quarter of 2016, pointing to the anti-immigration tone of the Trump campaign as a likely source of the increase.
Several related issues are addressed in a number of places in my new book,
Altered States. Some of the relevant findings are summarized below.
The Changing Immigrant Population
Chapter 3 addresses a number of different aspects of population migration (both immigration and internal migration) and presidential election outcomes. One important finding on this front is that, as a group, naturalized citizens have changed in many politically relevant ways over the past forty years. Whereas naturalized citizens used to "look" a lot like the native-born population in terms of race, ethnicity, party, and ideology, they are are now overwhelmingly non-white and have grown substantially more Democratic and liberal than the native-born population. These changes make the distinction between immigrant and non-immigrant voters increasingly politically important.
Size of Immigrant Population and Changes in Party Support
The figure below is adapted from Chapter 3 and illustrates the relationship between the size of the naturalized population and changes in party support in the states in presidential elections over the past forty years. The dependent variable is the change from 1972-1980 to 2004-2012 in the expected Democratic share of the statewide two-party presidential vote (purged of home-state and southern regional effects) centered on the Democratic share of the national two-party vote, and the independent variable is the percent of the state's citizen voting-age population (CVAP) in 2008 who were foreign born.
There is a clear positive relationship between percent foreign born and change in Democratic vote share, albeit with a bit of a curvilinear pattern. At low levels of foreign born population there is a mix of political outcomes, with Democrats making gains in some states and Republicans making gains in others. However, Democrats gained ground in virtually all states with an above average level of foreign born population. The only exceptions to this are Alaska and Texas (so much for Texas
turning blue). Otherwise, the entire lower right corner of the graph--high foreign-born population, coupled with Democratic losses--is empty.
All of the states with the highest levels of foreign born population (California, Florida, Hawaii, Illinois, Nevada, Massachusetts, New Jersey, and New York) are also among the states where Democrats made their greatest gains. It is worth noting that many of these states (California, Illinois, New Jersey) used to be fairly competitive but are now clearly in the Democratic camp, while others (Florida and Nevada) have moved from leaning Republican to being fairly competitive now.
The Increasing Importance of the Immigrant Population
Another of the interesting findings from
Altered States (Chapter 5) is that, over time, all manner of state-level demographic characteristics have become increasingly closely connected to presidential election outcomes in the states. As the figure below illustrates, this is certainly the case with the relationship between percent foreign born and party support in the states:
With the exception of the 1972 election, there was little-to-no relationship between the relative size of foreign born population and presidential outcomes in the states in the 1970s and 1980s, but the relationship has grown in strength steadily over time. The average election-year correlation was .18 from 1972 to 1980, .29 from 1984 to 1992, .50 from 1996 to 2000, and .56 from 2004 to 2012. Overall, the strongest correlation was .60, in 2012.
Swing States
The electoral impact of a growing and increasingly Democratic foreign-born electorate likely depends on its geographic distribution, playing a more pivotal role in swing states than in solidly Democratic or Republican states. Among a group of seven swing states (neither party has more than a two-point advantage) identified in Chapter 6 of Altered States, only one--New Mexico--is among the states with the slowest growth in foreign-born CVAP from 2000-2012, but three swing states--Florida, Nevada, and Virginia--are among the group of states with the fastest growing foreign-born CVAP in the same period. In a close national contest, these patterns of immigrant population growth could play a key role in determining the Electoral College outcome.
It's Not Just Latinos
Finally, it should be pointed out that while many of Donald Trump's more notorious statements about immigration have focused on Mexican and Latin-American immigrants, the naturalized citizen population (immigrants who can vote) is
comprised of just about as many immigrants from Asia (37%) as from Latin America (39%). This doesn't let Donald Trump or the Republican Party off the hook, politically, however, since Asian-Americans hold overwhelmingly
negative views toward Donald Trump and the Republican Party and
supported President Obama at slightly higher rates than Latinos did in 2012.