How much is Gerrymandering really Helping Republicans in Texas?

(From left to right) Texas’s 2nd, 33rd, and 29th congressional districts (Source: U.S. Geological Survey — https://nationalmap.gov/small_scale/printable.html#congress)

It is no secret that Texas has a long history of gerrymandering. From the multitude of Supreme Court and District Court cases surrounding unconstitutional districts in the state, to the districts’ bizarre shapes, one can hardly argue that Texas’s congressional districts were drawn with bi-partisan fairness in mind. But how effective has the creation of these intentionally discriminatory districts been in making safe, reliable districts that advantage the party in control of the redistricting process? Large metropolitan areas, of course, contain the most voters and the most diverse voter populations, making them the clearest targets for packing a specific demographic of voters into a single district to diminish their voting power. By looking at how a specific metropolitan area has been divided into different congressional districts over time and analyzing the effects of those redistricting plans, we can determine the effectiveness of this partisan practice.

(Source: Texas Legislative Council — http://www.tlc.state.tx.us/redist/history/maps_congress.html)

The U.S. Office of Management and Budget defines the Austin Metropolitan Statistical Area as the five counties of Travis, Hays, Caldwell, Bastrop, and Williamson. The last time these five counties were all in the same congressional district was the 1970 congressional elections. Since then, the Texas State Legislature has enacted six different congressional redistricting plans, with the latest plan imposing seven districts across the Austin Metro Area. This increase alone fails as evidence of gerrymandering, given that the population of the area is more than five times as large as it was in 1970. However, the growing number of congressional districts within the Austin Metro Area becomes far more interesting when compared against which political party controlled the Texas State Legislature when the redistricting plans were enacted, and how many districts those plans added to the area.

Partisan breakdown of the Texas Legislature over time (Source: Legislative Reference Library of Texas http://www.lrl.state.tx.us/whatsNew/client/index.cfm/2012/8/13/Legislative-Statistics-and-Trends)
(Source: Legislative Reference Library of Texas — http://www.lrl.state.tx.us/sessions/memberStatistics.cfm)

The first four redistricting plans issued after 1970 came from state legislatures with large Democratic majorities, with the first two plans each adding a single district to the Austin Metro Area, and the former two not adding any. Then in 2004, the 78th Texas Legislature, the first in the modern era with a Republican majority, added three congressional districts to the area, doubling the amount of districts within the area since the legislature’s previous redistricting plan, and the following plan, also drawn by Republicans, added another district to the area.

Still, the fact that recent Republican redistricting plans have added far more districts to the Austin Metro Area than past Democratic ones does not necessarily represent evidence of gerrymandering, as the practice does not to intend to simply divide cities into as many districts as possible, but to create districts that provide an advantage to the party controlling the redistricting process. This is done by creating two kinds of districts, one containing as many opposition voters as possible, and another containing a reliable but not overwhelming majority of voters favoring the party controlling redistricting. Not only should we expect this practice to reward the majority party with control over more districts than the opposition, but also that the margins of victory in districts won by the opposition should be higher than those in districts won by the majority.

* — Restricted to elections in Congressional Districts within Travis, Hays, Caldwell, Bastrop, and Williamson Counties, ^ — Restricted to elections in years in which Congressional Districts were drawn by State Legislature, also restricted to elections containing both Democratic and Republican candidates, ˚ — “Majority” and “Minority” meaning parties that were either in the majority or minority of the Texas Legislature when redistricting of contested Congressional Districts took place. Gaps in the graph represent elections in which either all majority or minority party candidates ran unopposed. Gaps can also represent elections in which either no majority or minority party candidates were elected. The graph begins in 1976 because the 1970 and 1972 congressional elections were won by Democrats who ran unopposed, with no Republicans winning election, and the 1974 congressional election utilized redistricting plan drawn by a court order. (Source: Office of the Clerk of the U.S. House of Representatives -http://clerk.house.gov/member_info/electionInfo/)
A close up of the graph above showing the turning point in Texas’s redistricting history. * — Restricted to elections in Congressional Districts within Travis, Hays, Caldwell, Bastrop, and Williamson Counties, ^ — Restricted to elections in years in which Congressional Districts were drawn by State Legislature, also restricted to elections containing both Democratic and Republican candidates, ˚ — “Majority” and “Minority” meaning parties that were either in the majority or minority of the Texas Legislature when redistricting of contested Congressional Districts took place. (Source: Office of the Clerk of the U.S. House of Representatives -http://clerk.house.gov/member_info/electionInfo/)

Before 2004, congressional elections in districts within the Austin Metro Area had widely varying margins of victory, with many incumbent candidates either running unopposed or winning in landslides. No clear pattern of margins of victory by majority and minority parties emerges until the 2004 elections, with Republicans, winning by a slightly higher average margin of victory than Democrats. The following three congressional elections could not have been influenced by gerrymandering, as they were subject to a Supreme Court redistricting plan issued after the 2006 case League of United Latin American Citizens v. Perry, which found that the 78th Legislature’s plan was in violation of the Voting Rights Act. The subsequent redistricting plan by the 82nd Legislature in 2011 resulted in elections whose average margin of victory by party closely mimicked those of the 2004 elections, with the Democratic average margin of victory increasing and the Republican average margin of victory decreasing in each successive election. By the 2016 congressional elections, the Democratic average margin of victory was nearly 10 points higher than that of the Republicans. This trend, which clearly becomes apparent in 2004 when Republicans took control of redistricting, confirms the aforementioned expectation that if gerrymandering is present, then the opposition party should win by a higher margin of victory than the party controlling redistricting.

While the data behind this recent trend is limited to only seven of Texas’s 36 congressional districts and only four congressional election cycles, it makes sense that the Austin Metro Area would be a prime target for Republican gerrymandering considering its reputation as a Democratic stronghold in a predominantly Republican state. In order test this reputation and find exactly how Democratic the Austin Metro Area has been since the beginning of Republican redistricting, we need to look at the partisan voting behavior of the area’s population in major statewide elections since 2004, meaning Presidential and Senate elections. In the eight such elections, beginning with the 2004 Presidential Election, voters in the Austin Metro Area have sided with the Democratic candidate in the six most recent elections, and the Republican candidate in the first two. Combining the results of all eight elections, 54.8% of votes were for Democrats, while 45.2% of votes were for Republicans, proving that the area’s Democratic reputation is well deserved.

(Source: Texas Office of the Secretary of State — http://elections.sos.state.tx.us/index.htm)
^ — Restricted to elections in years in which Congressional Districts were drawn by State Legislature (Source: Texas Office of the Secretary of State — http://elections.sos.state.tx.us/index.htm)

Despite the Austin Metro Area’s clear Democratic preference since 2004, the area was equally represented by Democrats and Republicans in 2004, and overwhelmingly by Republicans since 2012. Unsurprisingly, no incumbent Republican candidate has lost re-election in any of these elections. As it is unlikely that the partisan voting behavior of the Austin Metro Area population would differ significantly between major statewide elections and congressional elections, we can infer that voters from the portions of these congressional districts which lie outside of the Austin Metro Area are responsible for the high number of Republican congressional victories in recent years. This is exactly what Republican state legislators hoped their most recent redistricting plan would accomplish: offsetting the voting power of the Democratic Austin Metro Area population by dividing it into a multitude of districts also containing heavily Republican rural communities outside of the Austin Metro Area.

(From left to right) Texas’s 21st and 35th congressional districts (Source: U.S. Geological Survey — https://nationalmap.gov/small_scale/printable.html#congress)

Lamar Smith’s 21st district perfectly represents this practice, containing small, predominantly Democratic sections of Austin and San Antonio and a massive rural region to the west of these cities. In contrast, Lloyd Doggett’s 35th congressional district, the sole Democratic district in the Austin Metro Area, is made up of east Austin, the primarily Hispanic town of Lockhart, and east San Antonio, demonstrating how Democratic voters have been tightly packed together to minimize their influence. Rising margins of victory for the lone Democratic Congressman Doggett coupled with falling margins of victory for Republicans, is proof of how successfully Austin Metro Area Democrats have been crowded into one of the city’s congressional district, and spread evenly throughout the other six. Not only has Texas been severely gerrymandered, it has been done so with measurable effectiveness.

A redistricting map created by a computer algorithm using 2010 U.S. Census data to maximize compactness and equal populations among districts. The algorithm draws districts with respect to the boundaries of census blocks, the smallest geographic units used by the Census Bureau. This ensures that district boundaries reflect actual communities of interest, rather than state legislators’ desires to gain congressional seats for their party. Maybe someday Texas voters will get the fair districts they deserve. And maybe someday pigs will fly. (Source: http://bdistricting.com/2010/TX_Congress/)