In 2008 pundits said that the Republican Party was doomed. Then with the election results in 2010 many of the same pundits are saying the Democratic Party is doomed. This view has been compounded by people doing naïve analyses of the electoral vote changes resulting from the 2010 census. However, a closer look at these demographic trends yields a picture more favorable to Democrats than the commonly expressed interpretation would (Here is a map of population changes by county that might make for a good reference for this discussion).
The 2010 census revealed a shift in population from the Northeast to the South and West. With one exception, Michigan, all US states gained population between 2000 and 2010. But the size of those population gains has been higher in the South and West than in the North and East. This has led to a shift in the apportionment of congressional representation and Electoral College seats that seems to favor states that usually vote for Republicans. For example, eight states (AZ, FL, GA, NV, SC, TX, UT, and WA) gained congressional seats. Of those, Obama won three (FL, NV, WA) and two of those, FL and NV, are notoriously closely fought in most elections. On the other side of the equation, ten states lost congressional seats (IL, IA, LA, MA, MI, MO, NJ, NY, OH, and PA). Of those, Obama won all but two, LA and MO. Many people are taking this to indicate a shift in favor of Republicans for 2012 and beyond.
Two factors undermine the argument that the Republicans are going to clean up as a result of this shift: the increasing Hispanic population and the increasing urbanization of the South and West. Hispanics make up an enormously disproportionate share of the population growth in the highest growth regions of the country. This is politically relevant because Hispanics are also much more likely to vote Democrats and Republicans. This trend is showing few signs of changing as the Republican party becomes more and more associated with anti-immigrant, nativist attitudes and policies. Most worrying for Republicans, Texas, their great bastion of electoral votes, is becoming increasingly Hispanic at a much faster rate than the country as a whole. This could mean that even as Texas adds 4 Electoral College votes (!), it could be moving away from being completely safe for Republicans and towards something more like Florida where both parties can hold out hope of a win (I’m not saying this is going to happen overnight, just that this is the direction things are moving in Texas). Most of this has been well covered in the mainstream media. And of course the low rate of voter registration among Hispanics mutes this effect somewhat.
The effect of urbanization is perhaps much more important and has gotten much less attention. Urbanization is happening in both the high growth and low growth parts of the country. This is politically relevant because voters in urban areas are much more likely to vote for Democrats than are rural voters. For example, in Ohio, it used to be the rule that the Cleveland metropolitan area voted for Democrats and the less densely populated Central Ohio area was a Republican bastion. As the population of Cleveland declined and that of Columbus rose, many Republicans saw reason to believe that Ohio was becoming a solidly Republican stronghold. However, as Columbus grew it became increasingly prone to vote for Democrats and for the last several election cycles the county around Columbus has emerged as a safely Democratic bastion within Ohio even as Cleveland's influence on statewide results has declined. To link this with the discussion above, it's worth noting that the Hispanic share of the overall population of Franklin County (in which Columbus is located) has increased by 129% and the African American share of the population increased by 29% while the share of Franklin county that is "White" declined by 2%. That cannot be good news for an increasingly xenophobic and anti-urban Republican party.
Two examples of how urbanization impacts the population shift can instructive. Utah is one of the fastest growing states in the country but it’s not the rural areas of Utah causing that growth. Rather it is booming metropolitan area centered on Salt Lake City that is driving this growth. Utah is going to get another congressional seat (and Electoral College vote). And it is also true that Utah is overwhelmingly Republican in its voting history. That may mean that Utah’s extra electoral vote will likely go to Republicans for the foreseeable future. However, the congressional seat will likely have to lead to more representation for urban voters in Salt Lake City. Because the newly drawn districts in Utah will have to have roughly the same population within them and since most of the new population is concentrated in and around Salt Lake City, it will be hard to avoid, even with gerrymandering contortions, either creating an entirely new urban district or make several existing districts significantly more urban. So even in Utah, perhaps the safest state in the country for Republicans, the population shifts may pose some hard choices for Republicans and some opportunities for Democrats. When one considers that a lot of the population growth in Texas is not only Hispanic but concentrated in urban areas, like Houston, that are already starting to trend Democratic, one starts to see the fly in the demographic ointment for Republicans.
On the other side of the equation we have Iowa losing a congressional seat and an electoral vote. However, within that state, the population is becoming more urban (at least by Iowa standards). Most of the rural counties in the state are losing population while most of the population growth is concentrated in the relatively urban counties around Des Moines, Cedar Rapids, Waterloo, Iowa City, and Davenport. The new plan for the new districts has been proposed and is likely to pass. It combines the district in rural SW Iowa with the district around Des Moines. This new district would be the home district of the long standing incumbent Democrat who has represented Des Moines for several terms. The plan also shifts boundaries of the districts in such a way that the two Republicans who had represented two rural districts in NW and SW Iowa are now both residing in a single rural district in NW Iowa. At the same time, the boundary line between the two districts in the more urban eastern part of the state was shifted so that the two Democrats who represent those two districts are now both residing in the same district. One of those two Democrats lives very close to the boundary and has announced his intention to move to the other side of the boundary and take up residence in what would otherwise be a district with no incumbent, most of which had been part of his old district. The result is that while Iowa is losing a seat, it will most likely be a Republican who gets eliminated. A similar process is likely taking place in Illinois, New York and Pennsylvania. Only in Michigan and Ohio where large urban areas are in serious decay (Detroit and Cleveland) could there be some serious deviation from this effect.
America's population is shifting to the South and West, traditional strongholds of Republicans and conservatism. However, as it makes this shift, the American population is becoming more urban and less "White." The result of all of this could be that while the Republicans will see a short term advantage in the Electoral College, they will see a short and especially a long term disadvantage in Congress. And even the short term advantage in the electoral college may prove difficult to realize for Republicans as the vote rich, and once safely Republican, Florida becomes increasingly likely to vote for Democrats as its population also becomes more urban and more (non-Cuban) Hispanic.