Early voting in the Republican and Democratic Party primary runoffs begins on Monday, July 23, and ends on Friday, July 27. As the Texas secretary of state reports in-person early voting and mail-in absentee ballot totals for the 15 most populous counties next week, the data in the figure at right (click here for the full-size graph) will provide a rough guide to the evolution of early voting turnout in the GOP runoff primary compared to the first round of the primary held in May. They also will supply a tool with which to project the overall level of voter participation in the runoff.
In May there were 12 days of early voting, in contrast to five for the runoff. For comparison purposes, therefore, each of the five July early voting days (Monday=1, Tuesday=2, Wednesday=3, Thursday=4, Friday=5) was assigned the early voting/absentee voting totals from 2.4 of the early voting days in May in consecutive order. Thus for day 1 of the July runoff early voting (Monday, July 23) the vote totals from each of the first two days of early voting in May (May 14 and 15) along with the totals from 0.4 of the third day (May 16) are utilized. A similar format is followed for the remaining four days of runoff early voting.
It is difficult to predict both what actual turnout will be in the marquee race of the GOP primary, the Senate runoff between David Dewhurst and Ted Cruz (in the first round in May it was 1.4 million), and what proportion of the voters will vote early or by mail (in the 15 most populous counties, 51 percent of voters cast a ballot in the Republican Senate primary early or by mail during the early voting period of May 14 to May 25). A reasonable estimate of overall turnout in the GOP Senate primary would fall between 750,000 and one million, while it is very likely that the proportion of these Texans casting a vote early or by mail will be somewhere between 55 percent and 60 percent.
As the daily early voting results are posted by the secretary of state beginning on Tuesday, July 24, a comparison of the runoff cumulative vote totals with those from the May primary detailed here will provide an indicator, albeit rough and imperfect, of what overall voter turnout in the runoff election is likely to be. If, for instance, the cumulative vote totals reported by the secretary of state for each weekday next week divided by the corresponding cumulative total for that day in the figure is near 0.6, then that would suggest overall turnout in the runoff election is likely to be closer to the low mark of 750,000 projected above. In contrast, a ratio of the July to May cumulative votes approaching 0.9 would suggest an overall level of voter participation this round in the range of 1 million.
Mark P. Jones is the James A. Baker III Institute for Public Policy’s fellow in political science as well as the Joseph D. Jamail Chair in Latin American Studies and chair of the Department of Political Science at Rice University.