Former school board member Candace Valenzuela is the Democratic nominee in Texas' 24th congressional district after defeating Air Force veteran Kim Olson late Tuesday night.
The seat has been held by retiring Republican Kenny Marchant since 2005.
With 92% of precincts reporting early Wednesday morning in the primary runoff, Valenzuela held a 20-point lead over Olson.
Texas' 24th district includes parts of northeast Tarrant and northwest Dallas counties and a small portion of Denton County.
Valenzuela is a former member of the Carrollton-Farmers Branch ISD school board and garnered big-name endorsements from U.S. Rep. John Lewis (D-Atlanta) and U.S. Sen. Elizabeth Warren (D-MA).
"Now is the time to bring our country together and deliver real results. We cannot afford another representative in #TX24 that puts corporations and donors first," Valenzuela tweeted Tuesday night.
In addition to her military service, Olson served on the school board in Weatherford ISD and later as the human resources director for Dallas ISD.
Valenzuela will run against former Irving Mayor Beth Van Duyne, who has the backing of President Donald Trump.