Republican Rep. Mayra Flores lost to Democrat Rep. Vicente Gonzalez to represent the Texas border district.
Gonzalez came in with 52.7% to Flores' 44.3% on Wednesday, according to The Associated Press.
Flores flipped a House seat in June during a special election after Democrat Rep. Filemon Vela resigned in March to enter lobbying. Gonzalez last month claimed that Flores "stole" the House seat by winning the special election.
"The RED WAVE did not happen," Flores tweeted early Wednesday morning. "Republicans and Independents stayed home. DO NOT COMPLAIN ABOUT THE RESULTS IF YOU DID NOT DO YOUR PART!"
Gonzalez celebrated his win and said, "The people of South Texas have spoken."