Tag Archives: congressional districts

BREAKING: U.S. Supreme Court Gives New Life to Challenge to MD Congressional Districts

CDMDReversing a decision by the Fourth Circuit, the U.S. Supreme Court issued a unanimous opinion that a federal district court judge erred in dismissing a suit against Maryland’s redistricting plan on First Amendment grounds without letting it go before a three-judge panel. As a result, the case is remanded, presumably so that the petitioner can make his case before a three-judge panel.

Winning a rehearing on an appeal over improper procedure is a long way from winning the challenge. Still, it gives new judicial life to a debate over the legality over Maryland’s congressional redistricting plan that the State had thought had been put to bed. (h/t Rick Hasen).

The opinion of the court can also be found here:
Shapiro v. McManus (2015)


Rorschach Map of Incumbent Desires

Much has been made of the, ahem, “creative” boundaries of Maryland’s current congressional districts. A previous post provided more detailed maps that show the true artistry of the districts. But here is a statewide view that probably doesn’t do it full justice:

CDMDMaryland’s Current Congressional District Map

Many cite the non-compact boundaries as evidence of partisanship. Certainly, the 6th District was reconfigured to aid Democrats, who picked up the seat in 2012. However, Democrats did not have to draw these non-compact districts to gain a 7-1 majority in place of the previous 6-2 split. The following plan has seven districts that Obama won by 15% or more in 2008:

Obama15ptsAlternative Congressional Plan 1

While probably not the most compact plan that could be drawn, it also is clearly much more compact than the enacted plan. Beyond containing seven very Democratic districts, it also still contains two districts that are over 50% black in voting-age population.

A map that gave Democrats at least a 10% advantage in seven districts, again as measured by support for Obama in 2008, could be made even more compact and violate fewer county boundaries:

Obama10ptsAlternative Congressional District Plan 2

In this version, District 8 doesn’t reach the Pennsylvania border or take in any portion of Carroll County, which is no longer split. The Fourth District is also entirely within Prince George’s. Montgomery County has only two districts instead of three.

So why did the Democrats choose to adopt a plan with such meandering districts instead of a simpler version? According to many different sources, the answer lies in the desire to favor the preferences of certain incumbents, even when they were highly idiosyncratic and would not alter their reelection chances.

(1) Rep. Steny Hoyer insisted on continuing to represent UMD College Park, which he has represented since entering Congress. (Love the Turtle!) However, College Park is at the northwestern end of Prince George’s. Accommodating the desires of this powerful representative forced many other changes to plan.

For example, the 4th couldn’t continue to go into Montgomery if the 6th was to take in significant portions of that County, so the 4th now crawls around the edge of Prince George’s to enable it to scoop up Republican voters in Anne Arundel.

(2) Similarly, Rep. Dutch Ruppersberger sits on the intelligence committee and wanted to represent both Fort Meade and the Aberdeen Proving Ground. (Couldn’t we just buy him his own spy cam?) Even more creativity ensued as these two facilities lies at the opposite ends of the Baltimore region

(3) Rep. Elijah Cummings did not want to represent Carroll County, throwing yet another complication into the mix. Carroll is very Republican but would have easily been swamped by Cummings’ Baltimore base. So now Rep. Chris Van Hollen represents parts of Carroll County.

(4) Rep. John Sarbanes felt strongly that he wanted to continue to represent Annapolis, adding another layer of complexity into the plan’s requirements. Drafting a plan to satisfied this demand along with Ruppersberger’s helps explain how the 2nd and 3rd districts took on even more convoluted shapes.

(5) Complicating it all further was that so several representatives–Cummings, Harris, Ruppersberger, and Sarbanes–live with a small area near Baltimore. While living in the district is not required–just ask John Delaney–most prefer to do it.

And that’s how we ended up with this:


By the way, there is no legal impediment to gerrymandering for incumbents. Indeed, courts have cited it as a legitimate rationale for states to craft plans in a particular manner.


Congressional Plan Fairer Than You Think

CDMD2012 Congressional District Map

Redistricting remains one of the more contentious if arcane subjects in American politics. Unlike in many other western democracies with single-member district elections, such as Australia, Canada and the United Kingdom, the U.S. still usually allows politicians to draw both congressional and state legislative districts.

Some advocate that states ought to construct plans that are fair to Democrats and Republicans. And Maryland’s congressional plan has been attacked as unfair to Republicans not only by the GOP but by other observers, such as St. Mary’s College Professor Todd Eberly.

But how do you measure partisan fairness? Here are two basic principles that some see as underlining a fair plan that does not favor one party over the other along with an assessment of how well Maryland’s current plan lives up to them:

(1) No Partisan Bias. This principle is the simple idea that a party should win 50% of the seats if it wins 50% of the votes. Note that this is not the same as proportionality–that a party wins the same share of seats as votes.

There are different ways of testing for partisan bias. Examining the vote of statewide candidates in different districts is one simple way to test plans (not necessarily the best but easy to comprehend). The advantage of statewide candidates is that one can assess party performance with the same two candidates across all districts.

In this example, I use the presidential race. As is well known, Obama carried seven of the eight current districts in 2008. The two-party vote in each congressional district is shown in the first two columns:


Obama’s average vote share was 63.1%. But what if there was a uniform swing across all district of 13.1% towards McCain? Under this scenario, Obama and McCain would each have averaged 50.0% of the vote (see columns 3 and 4). Interestingly, each would also have carried four districts–exactly 50% of the total.

So the current plan passes a simple and cursory bias test. When each party receives 50% of the vote, each should win 4 districts.

(2) Symmetry reflects that if one party gains 65% of the seats with 55% of the votes, so should the other party. In single-member plurality elections, a party often gains a seat bonus when it wins more than a majority. This principle encapsulates the idea that such a bonus should be symmetrical and equal for both parties.

How symmetrical in Maryland’s plan? Again, examining the presidential vote is illuminating. In the example, below I envision a uniform swing across districts to estimate how many districts McCain would have won if he had received 63.1%–the share Obama actually won in the election.


The table suggests that McCain would have carried six districts–one less than Obama carried with the same share of the vote. So the plan is not perfectly symmetrical. The two black-majority districts (4 and 7) contain so many Democratic voters that even a Republican tsunami would not turn them blue, though the 7th comes close.

Examining the data in the table closely further suggests that Republicans would need only an additional 2.5% of the vote to carry all eight districts. However, Democrats would not achieve the same feat if they received the same vote share.

In truth, it can be very hard to construct plans free of bias and perfectly symmetrical. Moreover, swings are rarely uniform and the geographical concentration of partisans can shift over time. Of course, that also doesn’t mean we can’t often do better.

This at-first-glance examination also indicates that moaning about the partisan unfairness of the plan is not necessarily justified even though the plan was crafted by Democrats and one assumes designed to achieve their ends.

Complaints about the plan probably need to focus more on other issues. Next, I examine compactness–one of the major criticisms of Maryland’s redistricting plan.