An op-ed in the Washington Post from a young professor at Harvard:

By Ryan D. Enos, Published: March 8

Since the November election, in which President Obama won huge majorities among minority voters, it’s been taken as gospel that the Republican Party must, for its own survival, seek to appeal to those groups by moving to the left on topics such as immigration reform. But as the nation becomes more diverse, the demographic shift can cut the other way, too: Some Democratic voters are likely to move to the right.

It’s assumed that, as the United States becomes increasingly non-white, white Democrats will continue to support the party. But a substantial amount of social-science evidence suggests a different conclusion: As the United States becomes more racially and ethnically diverse, liberal whites might start leaning Republican.

Consider a straightforward experiment I conducted last year: Over two weeks, I sent pairs of Latino men in their 20s to ride commuter trains in the greater Boston area, often cited as one of the nation’s most liberal regions.

These people were not asked to do anything out of the ordinary, just to wait for the train and ride it. The pairs I sent were native Spanish speakers, so when they spoke to each other, it was probably in Spanish. To gauge other riders’ attitudes about Latinos, I surveyed them before the experiment and two weeks into the tests. In each case, the trains and times were randomly selected and were later compared with a control group of riders on different trains. These trains originated in communities with very few Latino residents, and the men I sent to ride the trains were often the only Latinos at those stations on a day-to-day basis. In this sense, the experiment was testing how people react when a very small group of Latinos moves to a new community.

The results were clear. After coming into contact, for just minutes each day, with two more Latinos than they would otherwise see or interact with, the riders, who were mostly white and liberal, were sharply more opposed to allowing more immigrants into the country and favored returning the children of illegal immigrants to their parents’ home country. It was a stark shift from their pre-experiment interviews, during which they expressed more neutral attitudes.

... In a more recent example, the city of Chicago began a massive effort in 2000 to overhaul its public housing. Large and notorious housing projects, such as Cabrini-Green, were demolished, and their residents were relocated. More than 99 percent of the relocated residents were African American. The outcome of the effort was the reverse of my experiment in Boston — rather than coming into contact, groups were separated.

Did that separation result in more liberal political views? Voting patterns among white residents living near these projects before and after their demolition showed that it did. After their African American neighbors left, fewer white residents turned out to vote, and voters became less likely to choose Republican candidates, whom they had previously supported at higher levels than had residents in other parts of the city. It seems that the contact with African Americans had politically mobilized whites in Chicago, similar to how Southern whites were mobilized in the 1930s.

To explore whether there was a similar effect among minority voters, in 2008 I conducted an experiment in which I sent a letter to African American voters just before an election in Los Angeles. The content of the letter was simple: It reminded people to vote and included a map noting how often people on their block voted compared with a nearby block. In some randomly selected cases, the comparison block consisted of African American residents; in others, it was largely Latino. When the letter pointed to a majority-Latino block, African Americans were significantly more likely to vote, suggesting that they were concerned about political competition with Latinos — even though both groups vote overwhelmingly for Democrats.

In that same year, I examined the voting of Latinos in Los Angeles and found that those who lived near predominantly African American neighborhoods were far less likely to vote for Obama than Latinos who lived farther away — suggesting that contact with their African American neighbors may have prompted them to vote against an African American candidate.

As different groups come into contact, people often have adverse reactions, and this can cause them to vote for a party that represents opposition to other groups. In today’s electoral landscape, that might mean white Democrats would be more willing to vote Republican. There is some evidence that when most people vote against their party identification — perhaps as a Reagan Democrat, just once — they return to their regular partisan identity within an election or so. However, if people make that switch during their impressionable years, in their teens or 20s, it can last a long time. ...

None of these findings bode well for Democrats. As ethnic groups mix, voters become more exclusionary and tend to vote for more racially conservative candidates — which may make it more difficult to maintain a diverse Democratic Party and could tilt the field in favor of Republicans.

The Boston-NYC-DC corridor that dominates punditry is simply a generation or two behind much of the rest of the country in exposure to the effects of illegal immigration.I did a quick analysis after the 2000 election that suggested that the type of minority mattered: in states with a lot of blacks, whites voted more Republicans, and in states with a lot of Asians, whites voted more Democratic, with the Hispanic impact falling in between. If your main complaint about your Asian neighbor is that you have to close the window when her six-year-old daughter starts her violin practice, you are likely to find the Diversity Narrative much more plausible than if your black neighbor holds pit bull fights in the back yard.But, of course, a huge advantage the Democrats have is holding the bullhorn that spews the Narrative. Their naturally rickety coalition of fringe groups would tend to turn on each other, but if the media can constantly gin up incidents, no matter how absurd, to elicit fear and loathing of the Straight White Gentile Man to unify the Obama Coalition, well, are you going to bet against the Democrats?