Updated at 10:40 p.m. with Lupe Valdez reaction

AUSTIN — Lupe Valdez defeated Andrew White in Tuesday's Democratic runoff for governor, making political history in a couple of ways.

Valdez, the former Dallas County sheriff, became the first Hispanic female and first openly gay person to win a major party's gubernatorial nomination in Texas.

White, a Houston businessman and son of the late Gov. Mark White, held steady in early returns but was overwhelmed as the evening wore on.

Valdez will now face the vastly better-known and more experienced Republican incumbent, Gov. Greg Abbott, in November.

"I am constantly hearing this is going to be such an uphill battle," she told supporters in Dallas.

"Please, tell me when I didn't have an uphill battle," she said. Was it when she had to take a city bus from the barrio and travel across San Antonio to get to school, or when she held "two to three jobs to get to go to college?" she said. "I am getting darned good at uphill battles."

Gubernatorial candidate and former Dallas County Sheriff Lupe Valdez makes her way to a podium after her runoff win at a democratic party celebration at Ellen's in Dallas on Tuesday, May 22, 2018. (Ashley Landis / Staff Photographer)

Valdez vowed to take the fight to Abbott. But there are obstacles.

As of Feb. 24, Abbott had more than $41 million stockpiled. Through six months as a candidate, Valdez couldn't raise a half-million.

Valdez, 70, struggled to master state policy issues and instill confidence among political insiders that she could somehow block Abbott's confident glide into a second term.

But she dismissed naysayers as underestimating her populist appeal.

"I am the candidate of the average, everyday Texan," she said in her victory speech. "And I will never, never, never stop working for you."

A daughter of migrant farm workers, Valdez said she had been underestimated all her life — and would surprise again.

Her victory over White, though, was surprisingly narrow.

Democratic candidate for governor Andrew White speaks to the media with his family beside him as he conceded to candidate Lupe Valdez at the Harris County Democratic Party headquarters, Tuesday, May 22, 2018, in Houston. (Karen Warren / Houston Chronicle)

It raised questions about the potency of her brand of identity politics. On the campaign trail, Valdez often stressed that she is female, Hispanic and lesbian.

She failed to crush White, however, in spite of enjoying support from labor, Planned Parenthood and other mainstays of the state Democratic Party's wobbly infrastructure.

The closeness of the runoff vote raised questions about whether White should have spent more of his money sooner.

White baffled observers, leaving many to wonder if his real runoff goal was to retrieve as much as possible of the slightly more than $1 million he had loaned to his campaign.

As of May 12, he had hoarded about $981,000 of campaign cash. During last week's early voting period, White spent some of that on direct mail and a limited TV buy in Austin.

While he may insist that his unconventional approach lent him the element of surprise, his post-runoff finance report will be scrutinized to see if he left resources untapped.

He said late Tuesday, though, that he was not leaving electoral politics any time soon.

"When you've seen what I've seen — from growing up in my father's home, to responding to Hurricane Harvey, and then as a candidate for governor in the best state in the nation — once your heart has seen what I've seen, you don't stop fighting," he said.

Frances Rizo, center, Sylvia Collins, right, and other supporters of gubernatorial candidate and former Dallas County Sheriff Lupe Valdez react to Valdez's win at Ellen's in Dallas on Tuesday, May 22, 2018. (Ashley Landis / Staff Photographer)

Valdez and White's tussle underscored a quandary Texas Democrats face as they look for a path out of the political wilderness, said Southern Methodist University political scientist Cal Jillson.

The party needs to cultivate and embolden Hispanics to register and turn out to vote, while also stoking the loyalty of "a high-turnout black constituency," he said.

But if the one-third of white Texans who vote Democratic begin to feel alienated from a party dominated by minorities, and either stop voting or vote Republican, the party's revival will be even tougher, he said.

"There's a 20-year gulf between where we are now and when a Hispanic electorate will help create a [Democratic] majority," he said. "They are playing to the future, but the future isn't this election cycle or the next one. It's a couple of decades out. And that's a hell of a drought when you've already been out of power statewide for 20 years."

White insisted he could reach middle-of-the-road Texans whom the party hasn't wooed in a long time. That would make his fall race against Abbott a far better bet than Valdez's, he insisted.

Valdez was not party leaders' first choice as they tried to woo younger Hispanic and black hopefuls into the governor's race last year.

But she may have at least one thing going for her as the fall race sets up, Jillson said.

U.S. Rep. Beto O'Rourke of El Paso is the Democrats' candidate to unseat GOP U.S. Sen. Ted Cruz.

O'Rourke, who is white, youthful and bilingual, has raised a lot of money and generated excitement with an endless procession of town halls, party officials said.

Jillson said the Democrats "are damned lucky that he's at the top of the ticket because that means Democrats going into the voting booth will see that race first and maybe decide to pull the straight-ticket lever for the last time." Last year, the Legislature passed, and Abbott signed, a bill abolishing straight-party voting, starting in 2020.

"If it were the governor's race at the top, there might be dispirited Democrats, particularly dispirited Anglo Democrats — that wouldn't pull that straight-ticket lever," he said.

Gubernatorial candidate and former Dallas County Sheriff Lupe Valdez, right, sits with supporter Katherine McGovern outside a primary runoff polling place at Walnut Hill Recreation Center in Dallas earlier on election day. (Ashley Landis / Staff Photographer)

Valdez enters the general election as the underdog.

Still, she could make even more history than she already has if she knocks off Abbott.

Texas has had two Roman Catholic governors — Abbott and Francis Lubbock, who was governor from 1861 to 1863.

Both, though, converted to Catholicism after marrying Catholics, Jillson noted.

"No born Catholic has ever been governor of Texas," he said. "Lupe would be the first."