Ted Cruz's campaign is counting on lower turnout, because he believes his supporters, who come from the more activist Tea Party segment of the GOP, are more energized to vote. Even in the middle of the summer.
"I believe we're on a path to victory, and the reason for that is simple: The runoff will be decided by the conservative grassroots, and the conservative grassroots are overwhelmingly supporting our campaign," Cruz said.
Audio: Ben Philpott's story for KUT News
And the fewer overall voters who turn out, the higher the percentage of those casting ballots fall under Cruz's "grassroots" label.
Cal Jillson, a political scientist at SMU, says watching early voting totals this week will provide some evidence of how well Cruz and Lt. Gov. David Dewhurst are doing in the runoff. In May, about 20,000 people a day voted in the Republican primary in the first five days of early voting.
"When we look at the beginning of early voting in this runoff, if we see early voting falling well below 20,000, down into the 12, 13, 14, 15,000 range, that's where Cruz will be very competitive because his more energized vote is likely to be there," Jillson said.
That has Dewhurst doing everything he can to mobilize his supporters. Especially in the Dallas-Fort Worth area. Last week, the Dewhurst campaign released a couple of major endorsements. Texas Rangers owner and baseball legend Nolan Ryan gave his support, along with former Senate candidate and Dallas Mayor Tom Leppert.
"We're seeing people calling in from around North Texas saying congratulations on the endorsement by Mayor Leppert,” Dewhurst said. “We voted for him, we're going to vote for you."
In May, Leppert used his name recognition in the Metroplex to get a three-way tie with Dewhurst and Cruz. Jillson says Dewhurst will need those votes to win.
"That doesn't mean all those votes move,” Jillson said. “But it does mean that in North Texas, that business-oriented, more moderate vote that Leppert and Dewhurst split is now available for Dewhurst to try to mine. And we'll see if he's able to do it."
Early voting continues through July 27. The runoff election is July 31.