But the results are seemingly contradicted by a Dewhurst internal poll, released to Roll Call earlier this week, that showed Cruz trailing 50-42 percent. Both polls claim a sample size of around 600 likely voters, and an identical 4 point margin of error. The contest has proven difficult to survey, with turnout likely a main factor in what should be a lightly attended runoff election.

Texas voters will head to the polls on July 31, with the candidate emerging from the Republican primary runoff the easy favorite for Texas's open Senate seat being vacated by retiring Sen. Kay Bailey Hutchison (R-Texas).