What’s an endorsement worth?

Photo by Bob Daemmrich for The Texas Tribune

The internecine warfare between the establishment conservatives (read: Texas House Speaker Joe Straus and lieutenants) and movement conservatives (read: Lt. Gov. Dan Patrick and the Freedom Caucus) has divided the Republican Party’s politics and legislative agenda. Divergences of tactics and topics have split Texas Republicans on issues of school vouchers, vaccinations, local control and property tax reform. Several high-profile primary elections feature challenges to incumbent Republicans, underscoring the ideological separation.

One way this battle plays out is in the shootout between Empower Texas and the Texas Association of Business, two groups representing the gunslingers facing off at high noon. Empower Texans has been vilified as a group of divisive scorecard keepers looking for party purity above practical politics. Conservative Republicans have demonized the Texas Association of Business (TAB) as a “liberal” interest group too willing to accommodate Democrats. Democratic strategists have hinted at a realignment that would bring business interests back to the Democratic Party, where they were after World War II to the 1970s.

Endorsements from groups like these serve as signals to voters about the relative alliances and issues a candidate may embrace and potentially come with access to campaign funds. But what are these endorsements worth?  Statistical estimation can help us identify how valuable these endorsements are in terms of actual votes.

To investigate, I conducted a series of analyses that allows us to statistically identify the number of votes (or the percentage of the vote) gained from each endorsement, considering all other relevant electoral factors like funds raised or incumbency status.

[The analysis estimates several ordinary least squares or generalized linear regression models, clustered on district. Only contested Republican races are included.  Total votes received in general primary or total votes received in runoff and the percentage are the dependent variable to be explained, including the following covariates: incumbent status, an endorsement by Empower Texans, an endorsement by Texas Association of Business, a sum of two cash on hand figures just before the 2014 or 2016 primary (the “8 Day before” Report, January report), percent male, percent in district with no high school degree, poverty status in past 12 months, percent citizen, and GINI Index of income inequality. The data were taken from the Texas Ethics Commission and the U.S. Census Bureau.  Hat tip to Jeff Blaylock at Texas Election Source for assistance with endorsement data.]

Evidence from the 2014 and 2016 primary elections (using only contested Republican races) reveals the value of an endorsement from Empower Texans is worth slightly more votes in a House GOP primary than an endorsement from TAB, but TAB’s endorsement is worth more votes in Senate races. But, the endorsement effect for both is relatively minimal in a runoff.

Specifically, an endorsement from Empower Texans is worth approximately 2,631 votes in a House primary where the average number of votes is just over 7,100. Put differently, an endorsed candidate would receive 2,631 more votes than a non-endorsed candidate.  The same endorsement by TAB is worth 2,064 votes in a House primary over a non-endorsed TAB candidate. The difference is about 567 votes.  In Senate races, which encompass a larger area with more voters (on average 21,560 with a maximum of over 64,000), an endorsement from TAB (20,106 extra votes) is more valuable than one from Empower (10,704 extra votes).

For both House and Senate races, the percentage won by those who were Empower endorsees was 14 percent greater than non-endorsed candidates, compared to a 1 percent bump of TAB endorsees over non-endorsed candidates. The effects for runoffs for both the House and Senate are not statistically significant, suggesting neither organization’s endorsement by itself provides a clear advantage, although there is a small negative effect for TAB-endorsed House candidates in runoffs (a 12 percent reduction in vote share).

The shifting political sands have made more conservative organizations like Empower a modestly more valued ally in Republican House primaries (and slightly overall) while TAB has an edge in Senate primaries, at least in the two most recent elections. The balance of power may yet shift. As the primary approaches and leadership within the party fractures over politics and policy, we’re likely to continue to see the loyal congregation divided.

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Brandon Rottinghaus

Professor, University of Houston