The fates of the three Republican incumbents in those races, Colleyville's Konni Burton, Dallas' Don Huffines and Houston's Joan Huffman, won't swing the partisan balance of the chamber. If all three keep their jobs, Republicans will have the majority of seats in the chamber. Same goes for if voters decide to remove all three. If any of the three GOP incumbents loses, however, that could make a dramatic difference in the ability of Lt. Gov. Dan Patrick to set the agenda for the Senate, which he presides over as president.
Burton, Huffman and Huffines are the most vulnerable Republicans up for re-election to the Senate, according to Rice University political science professor Mark Jones. Burton, who represents parts of Fort Worth, Arlington, Mansfield and Colleyville, faces a stiff challenge from moderate former Burleson School Board member Beverly Powell. Huffman and Huffines both represent districts that voted for Hillary Clinton over Donald Trump during the 2016 presidential election.
"If you have to keep changing the rules of the game to benefit yourself, that starts to make you look a little weak." — Mark Jones, Rice University
All three senators are a part of a 20-11 Republican majority in the Senate. That's important because of a procedural mechanism known as the three-fifths rule. The rule requires that three-fifths of the chamber's members — 19 — agree to let a bill be voted on before it goes to the floor. The rule used to be the two-thirds rule, but Patrick pushed for it to be changed before his first session in charge of the legislature in 2015.
As things are, Patrick can get anything he wants to the floor because Republicans control more than three-fifths of the chamber. If Democrats pick up two seats, reducing the GOP advantage to 18-13, Democrats will have, by a single member, enough votes to block Patrick's agenda unless Patrick changes the rules again.
"Nobody anticipates that Democrats will actually take control of the Texas Legislature, but if they're able to win enough seats to have blocking ability, that would seriously cramp Republicans' style," Southern Methodist University political science professor Matthew Wilson says. "That would be a real thorn in the side of Dan Patrick."
Even if Democrats lose two of the three races, Patrick could still be in a tough spot when it comes to agenda setting. Picking up just a single seat would leave Patrick with 19 GOP senators and no margin for error, giving Sen. Kel Seliger, a moderate Republican from West Texas and a political rival of Patrick's, a tremendous amount of power.
"[If one of the Republicans] loses, then Dan Patrick needs every Republican on board, and he just tried and failed to oust Kel Seliger," Jones said. "Even if Democrats only pick up one seat, Seliger is going to be a pivotal actor. He's going to be more assertive than he was last session because one, he doesn't have to face re-election and second, his opponents threw everything they had at him [during the 2018 primary], and he still avoided a runoff."
Faced with either scenario, Patrick could make it the 18-31sts rule or allow a simple majority vote to bring a bill to the floor. Patrick could change the rule with a simple majority vote, but Jones doesn't think the lieutenant governor will.
"It's one thing to go from a two-thirds to a three-fifths, but there's no really normal fraction down there [below three-fifths]," Jones says. "Patrick would start to look pretty weak then. If you have to keep changing the rules of the game to benefit yourself, that starts to make you look a little weak."