Overall turnout may not exceed 7% for both parties combined, according to the Texas Election Source, who also noted that turnout would be 3 points below 2012. 

With a majority of the precincts counted, the unofficial election night results are: 

Republican Primary Runoffs

CD 4 with 100% of the precincts reporting
John Ratcliffe captures 52.8% of the vote over Inc. Ralph Hall

CD 23 with 94% of the precincts reporting
Will Hurd captures 59.4% of the vote over Francisco "Quico" Canseco

CD 36 with 99% of the precicts reporting 
Brian Babin garners 57.8% of the vote over Ben Streusand

Lieutenant Governor with 94% of the precincts reporting
Dan Patrick captures 65.2% of the vote over Inc. David Dewhurst

Attorney General with 94% of the vote of the precincts reporting
Ken Paxton garners 63.9% of the vote over Dan Branch

Agricultural Commissioner with 94% of the precincts reporting
Sid Miller garners 53.2% of the vote over Tommy Merritt

Railroad Commission Place 2 with 94% of the vote of the precincts reporting
Ryan Sitton captures 57.1% of the vote over Wayne Christian

State Board of Education District 11 with 94% of the precincts reporting
Inc. Patricia "Pat" Hardy garners 58.6% of the vote over Eric Mahroum

SD 2 with 100% of the precincts reporting 
Bob Hall with 18,230 votes garners 50.4% of the vote over Inc. Bob Deuell with 17,930 votes

SD 10 with 95% of the precincts reporting
Konni Burton captures 60.2% of the vote over Mark Shelton

HD 10 with 100% of the precincts reporting
John Wray garners 52.9% of the vote over TJ Fabby

HD 16 with 100% of the precincts reporting
Will Metcalf garners 62.1% of the vote over Ted Seago

HD 53 with 94% of the precincts reporting
Andrew Murr captures 61.0% of the vote over Rob Henneke

HD 58 with 100% of the precincts reporting
DeWayne Burns captures 52.7% of the vote over Philip Eby

HD 66 with 100% of the precincts reporting
Matt Shaheen captures 54.3% of the vote over Glenn Callison

HD 102 with 100% of the precincts reporting
Linda Koop captures 59.8% of the vote over Inc. Stefani Carter

HD 108 with 100% of the precincts reporting
Morgan Meyer garners 74.4% of the vote over Chart Westcott

HD 129 with 98% of the precincts reporting
Dennis Paul garners 52.3% over Sheryl Berg

HD 132 with 68% of the precincts reporting
Mike Schofield captures 69.3% of the vote over Ann Hodge

Democratic Primary Runoffs

US Senator with 93% of the precincts reporting
David Alameel garners 72.6% of the vote over Kesha Rogers 

Agricultural Commissioner with 94% of the precincts reporting
Jim Hogan captures 53.7% of the vote over Richard "Kinky" Friedman

State Board of Education District 13 with 86% of the precincts reporting
Erika Beltran garners 66.4% of the vote over Andrea Hillburn

HD 76 with 88% of the precincts reporting
Cesar Blanco garners 67.5% of the vote over Norma Chavez

HD 105 with 67% of the precincts reporting
Susan Motley captures 74.4% of the vote over Terry Meza

Election Night Returns can also be viewed on the Texas Secretary of State website.