Lupe Valdez has defeated Andrew White in the Democratic runoff for governor, according to unofficial returns.

With more than 80 percent of precincts reporting, Valdez opened a 5 percent lead over White after being virtually tied with the Houston businessman earlier in the evening. She rode a strong showing in Dallas County, where she had served as sheriff, and neighboring Tarrant County.

White, the son of late Gov. Mark White, saw a big boost from his home county of Harris and adjacent Fort Bend County, but it wasn’t enough to overtake Valdez.

Valdez will challenge Republican Gov. Greg Abbott in November. She finished ahead of White in the March primary, getting 43 percent of the vote to White’s 27 percent, as both emerged from a crowded field that included seven little-known candidates.

The runoff period was highlighted by White’s weeks-long push for a debate with Valdez, which she ultimately agreed to earlier this month after a tumultuous stretch that saw her lose an endorsement to White from a group of young Hispanic activists. At the debate, they clashed over long-simmering issues in the race: Valdez’s cooperation with federal immigration authorities as sheriff, White’s personal opposition to abortion and whether Democrats should nominate a self-styled “moderate” in White.

Valdez will face a uphill battle against Abbott, who boasts high approval ratings and a $41 million war chest. She also will be fighting recent Texas history: The state’s voters have not elected a Democrat to statewide office in more than two decades.

This article originally appeared in The Texas Tribune at The Texas Tribune is a nonprofit, nonpartisan media organization that informs Texans — and engages with them — about public policy, politics, government and statewide issues.