More than 6.4 million ballots were cast in Texas through the end of Thursday, according to the latest figures. That is well above the state's previous early-voting record for a non-presidential election year, which was 5.5 million in-person early votes in 2018. The figures do not break down votes by party and do not include mail-in ballots. Early voting ends Friday, and Election Day is Tuesday.

The turnout comes as voters weigh a closely watched U.S. Senate race between Republican Ken Paxton and Democrat James Talarico. Contests for governor and other statewide offices are also on the ballot. Texas has added about 3 million registered voters since 2018 and now has more than 19 million.

Brandon Rottinghaus, a political science professor at the University of Houston, said the Paxton-Talarico race is the main driver of turnout. "There's no doubt that competition drives turnout," he said. He said he could see as many as 10 million ballots cast this midterm, which would top the 8.3 million votes cast in 2018. According to AdImpact, which tracks political ads, more than $560 million has been spent on ads and reservations across the primary, runoff and general elections. The Secretary of State's office declined an interview request.