New Census data shows us which congressional districts are growing—and why

The Census Bureau recently released new data from its annual American Community Survey, which fills the gaps between decennial censuses and asks a lot of questions the standard census doesn’t have room for. One great data set of particular interest to election watchers is the racial and ethnic demographics of the nation’s congressional districts, which offers us information not just about demographic growth (and shrinkage) but can also provide clues about the partisan direction of various regions around the country.

We’ve assembled the latest data in an easy-to-read format on Google Docs. There you’ll find complete racial and ethnic breakdowns for every congressional district according to the ACS’s one-year estimates for 2014. And along the bottom, you’ll see tabs showing estimates for 2013 and 2012 as well, which will give you a sense of how and where things have changed in recent years.

Below we’ve decided to take a look at the largest shifts on the district level among the country’s four biggest racial and ethnic groups: whites, blacks, Asians, and Hispanics. To smooth out the trendlines a little bit, we’re comparing 2014 to 2012, but even in that relatively short timeframe, some of the movement has been dramatic.

We’ll get to NY-07 in a moment. In the meantime, in MI-09, we’re likely seeing an influx of African Americans from Detroit moving out to the suburbs. CA-15, which takes in turf south of Oakland, was already one of the most heavily Asian districts in the nation; most of the growth among Asian-Americans there has come from Indians and Filipinos, while the Chinese population has actually shrunk. And in FL-27, which sits in the state’s far southeastern corner and covers part of Miami, has seen a big increase in its already sizable Cuban population.