Evidence abounds that Democrats and Republicans really do not like each other. Researchers have found that they avoid dating one another, desire not to live near one another and disapprove of the idea that their offspring would marry someone outside their party (see here, here, here). Sure, most people are not very political, but among those who are, partisanship seems to be affecting nonpolitical realms of their lives.
That phenomenon motivated a colleague and me to gather data about mixed-partisan marriages. We were curious: How many Americans are married to someone of the other party? Who are these people? Are they old or young? Where do they live? Do they vote? [...]
Second, 55 percent of married couples are Democratic-only or Republican-only, which raises a question: Is that a big number or a small number? In other words, is there more or less partisan intermarriage than we should expect? Here are two ways we try to answer that. We can compare interparty marriages to interracial marriages. Using voter registration data, we can do this in three states, Florida, Louisiana and North Carolina, where public voter files list everyone by their party affiliation and their racial identity. In those states, 11 percent of married couples are in Democratic-Republican households. In comparison, only 6 percent of married couples are in any kind of interracial household. At least in these states, there’s about twice as much interparty marriage as interracial marriage. [...]
If you have an image in your head of a “battleground neighborhood” that is fiercely divided between Democrats and Republicans, you might imagine tension between neighbors. But the truth is that in these neighborhoods, half of the married couples living under the same roof are not one-party pairs. In fact, except in overwhelmingly Democratic neighborhoods (which tend to be African-American neighborhoods), close to half of households are not Democratic-only or Republican-only. This is likely to contribute to a more tempered political climate in battleground areas than we might first expect.