Background

In the last installment of this series, we discussed how a legislative (specifically, the state House) redistricting plan might look if a partisan Democratic (and a Republican) redistricter were to draw the lines, given recent population estimates. In this final installment, we will redraw the state’s Senate districts.

Given the change in voter registration between April 2010 (when the US Census was taken) and December 2013, JMC estimates that the current population of Louisiana is 4,580,251, or a 1.0% population change in 3.5 years (for comparisons sake, the most recent Census estimate has Louisiana’s population at 4,601,893). Given this estimated population, a state senate district (there are 39 of them) would have an ideal district population of 117,442.

Current Districts

Black majority districts: 11

Districts David Vitter carried in 2010: 28 (27 with at least 50% of the vote, and 1 with a plurality)

Districts Charlie Melancon carried in 2010: 11 (11 with at least 50% of the vote, and 0 with a plurality)

Current Senate District Map

The current district lines for Louisiana’s state senators have been in place since 2011. What made that reapportionment tricky were two constraints: (1) substantial population losses resulting from Hurricane Katrina’s devastation in the New Orleans metropolitan area, and (2) the Voting Rights act, which spells out “appropriate” minority representation. These constraints resulted in a two New Orleans area state senate seats being relocated closer to the Baton Rouge area, which saw noticeable population growth. Furthermore, a district in central Louisiana was reconfigured to have a black majority.

Since 2010, there has been continued population growth in the area between Baton Rouge and New Orleans relative to the rest of the state,  although (as of 2013), the population changes aren’t enough for those parishes to gain additional seats.

Democratic Redistricting

Black majority districts: 11 (same as the current plan)

Districts David Vitter carried in 2010: 25 (24 with at least 50% of the vote, and 1 with a plurality) (3 less than the current plan)

Districts Charlie Melancon carried in 2010: 14 (13 with at least 50% of the vote, and 1 with a plurality) (3 more than the current plan)

Proposed Democratic Senate District Map

Given that Democrats are outnumbered 13-26 in the state senate, a Democratic redistricter would want to maximize the size of the Democratic delegation by (1) concentrating Republican voters into a minimum number of districts, and (2) diluting Republican strength in districts with a sizeable Democratic minority to enable Democrats to pick up those seats (note: voter registration statistics and the Vitter/Melancon numbers from 2010 were what we used to measure the partisan intensity of a given district). The following are the specifics of what a partisan Democrat redistricter might do:

(1)  Add Democratic voters to three Republican held Senate seats (one in the River Parishes, one in Morgan City, and one on Shreveport) to “flip” these seats to the Democrats;

(2) Reduce the Republican voting strength in five state Senate districts (one in the Florida Parishes, one in Ascension Parish, one in Lake Charles, one in Northeast Louisiana, and one in northwest Louisiana);

(3) Maintain the marginal political status of one of the Westbank districts under the assumption that with its 32% black voter population, unionized voters, and Democratic voting base (Obama’s percentage improved from 41 to 47% here between 2008 and 2012), Democrats would be competitive here in 2019;

Below are the more detailed “Democratic” maps for northwest/southeast Louisiana:

Detailed Democratic map for North Louisiana

Detailed Democratic map for SE Louisiana

Assuming that the Democrats were successful in every seat the attempted to flip (there is also a black majority seat in Acadiana held by a Republican that voted 61% for Barack Obama in 2012), they theoretically would gain 10 seats purely from redistricting and retake the Senate with a 23-16 majority.

Republican Redistricting

Proposed Republican Senate District Map

Black majority districts: 11 (same as the current plan)

Districts David Vitter carried in 2010: 28 (28 with at least 50% of the vote, and 0 with a plurality) (same as the current plan)

Districts Charlie Melancon carried in 2010: 11 (11 with at least 50% of the vote, and 0 with a plurality) (same as the current plan)

Since the Republicans currently have a 26-13 majority in the state House, their focus would be more defensive in nature (i.e., protection of its majority by shoring up members representing politically marginal districts), as there are only three  Democratic held seats that could be flipped.

Given these realities, here are the specifics of what a partisan Republican redistricter would do:

(1)  Make two Democratic held districts more favorable to the Republicans: one in the River Parishes near New Orleans, and the other in the Florida Parishes (note: the seat in the Florida Parishes already is Republican friendly, and has a term limited Democratic incumbent);

(2) Strengthen the four Republicans holding politically marginal districts: one in the Westbank, one in Lake Charles, one in the River Parishes, and one in northwest Louisiana;

Below are the more detailed “Republican” maps for northwest/southeast Louisiana:

Detailed Republican map for North Louisiana

Detailed Republican map for SE Louisiana

Assuming the Republicans were completely successful, they theoretically could gain two seats purely from redistricting, which would put them at a 28-11 majority. And unlike the House plan, the number of black majority seats would remain at 11. The major point of contention with this plan, however, would be that New Orleans would lose another seat (that seat would be relocated to the River Parishes).

Conclusion

Any redistricting plan that would be considered would inevitably be tweaked to satisfy the preferences of those serving on the Senate (and to some extent, the House) Governmental Affairs Committee. Furthermore, depending on who is in the Governorship and/or the legislative leadership by 2021, the applicable politics that would play out may be different. Finally, there is a third intangible to consider: depending on who gets elected in the 2015 and 2019 election cycles, different districts may be targeted and/or defended.

Still, given the population estimates as of December 2013, these contrasting plans can be thought of as an early “snapshot” of what the state Senate districts drawn for the 2020 Census might look like from either partisan extreme.