Florida Redistricting: Democrats' Structural Disadvantage

Democrats have a voter registration advantage in Florida, but a new study shows that Republicans would have an edge in a map with compact, contiguous legislative or congressional districts. That's because Democrats are concentrated in a few urban areas.
by | September 28, 2010

Florida will vote on two redistricting reform initiatives in November, one to set standards for congressional redistricting and one to set standards for legislative redistricting. Both mandate the same standards: Districts lines should be compact, contiguous, respect minorities and refrain from helping a particular political party.

These measures have been championed by most Democrats and opposed by most Republicans. That's because Republicans hope to have complete control of redistricting (though, with regard to congressional redistricting, they'd need to win the tough governor's race). Democrats think the rules will curtail the Republicans' gerrymandering ambitions.

But, the Orlando Sentinel highlights a study that shows that even "fair" districts might give the G.O.P. an edge, despite Democrats' voter registration advantage in Florida. The story:

Earlier this month, researchers from Stanford University and the University of Michigan presented a yearlong study of where Florida voters live that ran thousands of complex simulations of elections in computer-drawn contiguous and compact districts.

Their models found that even using maps drawn by nonpolitical algorithms, Republicans would still win 59 percent of all the districts.

That's basically because more Democratic voters live in concentrated clusters in urban cores, while Republican voters are spread out along the suburban and exurban landscape, they concluded.

Note that the study doesn't suggest that Democrats would be worse off with the measures passing than not. Rather, Democrats just wouldn't be as well off as they might hope or expect.

Still, what the researchers found in Florida is a large and largely unnoticed structural factor that boosts Republicans nationwide. Democratic voters are concentrated, which, in a district system, isn't a good thing.

One of the simplest illustrations of this point is to look at the Cook Political Report's Partisan Voting Index, which evaluates how Republican or Democratic congressional districts are by comparing their presidential votes to the national presidential vote. The most Republican congressional districts in the country are Alabama-6 and Texas-13, which come in at R+29.

In contrast, just in Illinois there are four districts that are greater than D+30 -- all of them with large minority populations. There are several other D+30 or more districts around the country. If some of those Democrats lived in more politically competitive places, the party would have an easier time building a House majority.

One lesson you might take away from this is that Democrats would be better off with a proportional representation system -- If Democrats get 52% of the vote for Congress or for the Florida legislature, they get 52% of the seats. But, that's not a safe conclusion for reasons Nate Silver mentioned last week:

Another finding is that Democrats do better in the average district than in the aggregate popular vote.  Since 1994, they have won the average Congressional district by 3.3 percentage points — even though in the aggregate popular vote, they’ve been essentially tied with Republicans.

This sounds like a paradox, but the reason for it is that Democratic-friendly districts — which often have more minorities and young voters — usually have lower turnout than Republican-friendly ones. Compare a district in which the Republican wins by 10 points and 500,000 people vote, to one in which the Democrat wins by 10 points and 300,000 people vote. Between these two districts, the Republicans will have received more total votes, since the Republican win will have come on heavier turnout. But the margin between the two parties in an average district is zero. This is similar to what happens in House elections in the real world.

This study in Florida also is a good illustration of the tension between various redistricting reform principles. Reformers want more compact districts. Reformers also want more politically competitive districts. But, when a political party's supporters are concentrated in a particular area, it's hard to get both.

Josh Goodman
Josh Goodman  |  Former Staff Writer

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