Rep. Ruth Jones McClendon (D-San Antonio) recently announced she would not seek re-election. In response to a subscriber’s question about how many votes it might take to reach a runoff in the race to succeed her, we provided the following:

HD120 has not been competitive from a House race standpoint for a long time. Rep. McClendon has received no less than 83% of the vote in any legislative race she’s run, and she has unopposed most of the time. That said, there are a few data points that might illuminate any run for her open seat:

  • There are around 88K registered voters in HD120.
  • 2014 primary turnout was 5.9%, which turned out to be higher than the 2012 presidential primary, when 4.9% turned out.
  • These are both significantly lower than in 2008, when Barack Obama was running for the first time and his nomination was not yet secure. I did not draw up a district number, but overall Bexar Co. turnout for the Democratic primary was 23.5%.
  • Turnout for the 2014 SD26 runoff within HD120 was 4.8%. About 58% of HD120’s RVs were eligible to vote in that election.
  • Turnout for the 2015 mayoral runoff within HD120 was 12.2%. About 56% of HD120’s RVs were eligible to vote in that election.

Let’s look at three turnout scenarios for the 2016 Democratic primary:

  1. 5.5% — average of the last two primaries’ interest level
  2. 12% — mayoral election interest level
  3. 18% — roughly halfway between mayoral interest level and 2008 interest level

Those turnout percentages translate into roughly 4,800, 10,500 and 16,000 votes cast in the district. In most 4- to 6-way primaries, a generally safe goal to make the runoff is 30% of votes cast, which would be 1,440 votes in the lowest turnout scenario, 3,150 votes in the middle scenario and 4,800 in the high scenario.

So I’d say at least 3,000 would be needed to have a strong shot at making a runoff, but it could take more than 5,000 to reach a runoff if turnout approaches 2008 levels. If turnout is closer to 2012 levels, then 3,000 wins easily and 1,500 would be competitive.