(I like this map, from here.)
After the 2012 election, "demographics are destiny" became a popular phrase. As the country diversifies, so the story goes, pretty much everywhere will trend Democratic.
There's no denying that many diversifying areas have trended Democratic. But there are interesting exceptions. Consider Palm Beach County, Florida. It diversified, but trended Republican. Was it because of older people? Jewish people? Rich people? None of the above? Let's see what we can find out.
Palm Beach County doesn't fit many of the stereotypes of a Republican-trending area. It isn't Appalachian or (culturally) Southern. And it's diversifying. The county's non-Hispanic white population shrank by a full 10% from 2000 to 2010, according to the Census.
In fact, over that period, few Florida counties diversified by as much as Palm Beach County:
But there's an evident Republican trend.
Barack Obama barely improved in Palm Beach County over John Kerry, in 2008. In 2008, Obama got 61.51% of the (two-party) vote. In 2004, John Kerry got 60.71% of the vote.
Perhaps Palm Beach County is simply "inelastic". And it's true that Democrats generally get around 60% in Palm Beach County (then again, Democrats generally get around 50% in Florida, at least in these elections).
But in 2012, Obama got 58.56% of the two-party vote--so he did worse than Kerry, and had a greater decrease than he had nationally, either from 2004-2012 (obviously) or from 2008-2012:
Going back to 2000, Gore (62.3%) and Nader (1.3%) combined to 63.6% of the (overall) vote.
In PVI terms, Palm Beach County has lost about half of the Democratic advantage it had in 2000 and 2004, when it was about D+12. In 2008, it was D+8, and in 2012, it was less than D+7.
And no, this isn't just about Barack Obama. Compare Bill Nelson's 2006 and 2012 performances by county, or compare Alex Sink's Gubernatorial performance in 2010 with Jim Davis' Gubernatorial performance in 2006. Nelson declined nearly everywhere from 2006 to 2012, but his decline in Palm Beach County was greater than his statewide decline. Davis had a solid loss, and Sink nearly won, but Sink actually did a bit worse in Palm Beach County than Davis.
In every case, Palm Beach County trended Republican relative to the state or national swing, whether the Democrat improved overall (2004 vs. 2012 Presidential, 2006 vs. 2010 Gubernatorial) or declined overall (2006 vs. 2012 Senatorial). In most cases, Palm Beach County trended Republican in absolute terms, too. (I think the only exception there is Obama's tiny improvement over John Kerry in 2008.)
That's a Republican trend.
The basic partisan geography:
Unfortunately, official Palm Beach County results for the 2004 election don't seem to allocate by precinct, but we can make precinct maps for the 2008 election (using Dave's Redistricting App and Census/TIGER shapefiles) and for the 2012 election (using election results and shapefiles from the Palm Beach County supervisor of elections).
This map shows Obama's performance by precinct in 2008 and Obama's performance by precinct in 2012.
(In both cases, I'm not including a handful of votes attributed to precincts that don't have shapefiles, and the precinct totals for 2008 don't quite sum to the certified total I don't think I can only work with what I have.)
There's a lot of information here. One of my favorite factoids: That single red precinct surrounded by blue is the tiny town of Atlantis, which seems to mostly be a golf course.
But where are the Democratic areas?
First, and unsurprisingly, there are the majority-minority areas. Let's compare Obama's 2012 performance to the 2010 Census numbers (by 2008 precinct):
There was a high overall correlation between non-Hispanic white population and Obama's performance in 2008 (when we can compare them by precinct using Dave's Redistricting App).
What about that cluster of extremely white precincts where Obama did very well in 2008?
Interestingly, they overlap pretty closely with the oldest Census tracts. Or, at least, with the largest cluster of Census tracts where a large of the population was 60 or older. And Obama still did well there in 2012:
This area is King's Point/West Delray Beach, and it's heavily Jewish (see below).
The 2008-2012 Trend, and possible explanations:
Palm Beach County helpfully provides a precinct conversion chart. Using this chart, I was able to divide Palm Beach County into comparable "clusters" of 2008/2012 precincts, and directly compare Obama's two-party share in the two elections.
The following map shows that comparison:
Obama did better than in 2008 on the shore of Lake Okeechobee and in the Westgate/Palm Springs/Lake Worth Corridor area.
Obama did worse than 2008, often considerably worse, nearly everywhere else.
For example, in the northern part of the county contained in FL-18, currently represented by Democrat Patrick Murphy, Obama received close to his national numbers in 2008, winning the area with about 52.5% of the vote, judging by Dave's Redistricting App. But in 2012, Obama lost the area, getting 47.6% to Romney's 51.75%, according to the DKE spreadsheet.
Hopefully, this trend map refutes the idea that Palm Beach County is simply "inelastic".
As you can see, there's a stark regional divide. What explains the Democratic-trending areas?
Let's compare the "trend" maps to various other maps. Here's the most convincing comparison, to my eyes:
House District 87, where the non-Hispanic white population plummeted from 50.9% in 2000 to 29.5% in 2010. But I don't know how much change happened here from 2008 to 2012. (And House District 86, to its immediate west, diversified quite a bit as well, but doesn't show the same trend.)
The biggest exception seems to be some of Riviera Beach, where Obama didn't seem to improve all that much relative to the Hispanic areas, and which is majority-African-American.
Without getting into a discussion about the (very real) dangers of ecological analysis, I think it's pretty clear what's going on.
Obama did considerably better among Hispanics, a little better or about the same among African-Americans, and quite a bit worse with non-Hispanic whites.
Again, I can't directly compare 2004 precincts, but there's every reason to think the same was true from 2004-2008, especially at the PVI level.
Another explanation I've heard suggested: Is this just because old people trended Republican? Maybe, but compare the trend map with the age map.
It is true that most of the oldest areas trended Republican, but that might just be because they're mostly some of the whitest areas. And the northern part of Palm Beach County, the part in FL-18, trended Republican, but isn't particularly old, apparently, or at least not all of it. Also, the heavily-Democratic "oldest" area seems to have trended Republican a bit less than some of the surrounding areas.
Another suggestion was: Is this just because rich people trended Republican? I think that's a little more likely. Compare the trend map to this map showing median household income by Census Tract.
All of the majority-minority areas seem to be low-income (sigh), but gradations among higher-income Census tracts seem vaguely associated with gradations in the trend map. The FL-18 part of the county basically all trended Republican, and it's basically all pretty high-income. The higher-income parts of South Palm Beach County seem to have trended Republican a bit more than the lower-income parts.
Finally, alas, people have understandably wondered: Is this just because Jewish people trended Republican?
Unfortunately (if understandably), neither the Census nor the American Community Survey keeps track of religion. However, the Jewish Databank has a study from 2005, with Jewish households by zip code.
Again, while Jewish areas trended Republican, if anything, it looks to me like some of the most Jewish areas trended less Republican than some of the surrounding areas. And, once again, an explanation based on Jewish people trending Republican doesn't explain why the FL-18 part of Palm Beach County trended Republican. But it's entirely possible that, for example, the Jewish areas immediately west of Boca Raton (on the border with Broward County) trended Republican for one reason, and the part of Palm Beach County in FL-18 trended Republican for another reason.
But here's what Palm Beach County illustrates: increasing diversity isn't a guarantee of improving Democratic performance.
The assumption behind "demographics is destiny" is that partisan preference will stay constant within an ethnic group. But, in Palm Beach County, there seems to have been a lot of change within ethnic groups. Hispanic areas got more Democratic, and white areas got more Republican, from 2008 to 2012.
The 2012 election was more racially polarized, then, and not merely because Democrats improved with nonwhites. There's every indication that Democratic performance actually declined among non-Hispanic whites.
And the result, in Palm Beach County, was a decline in overall Democratic performance.