Republican businessman Gary Gates defeated Democratic educator Eliz Markowitz in the special election runoff for House District 28, keeping the seat under GOP control despite a vigorous and nationally watched effort by Democrats to flip it.

Gates’ decisive win came after Markowitz marshaled the support of several Democratic presidential candidates, touted a poll showing a neck-and-neck race and raised hundreds of thousands of dollars from groups outside Texas.

Democrats viewed the Fort Bend County race as a chance to display strength ahead of the fall 2020 elections, when they aim to regain control of the Texas House by flipping a number of rapidly diversifying suburban seats that are similar to House District 28, albeit less conservative.

With 100 percent of Election Day results in, Gates won 58 percent of the vote, roughly doubling the margin of victory recorded in 2018 by Republican John Zerwas, the seat’s prior occupant.

At his election night watch party in Richmond, Gates cast the result as proof that Republicans could “prevent many seats from flipping” in 2020, “and maybe even take some back.”

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The Texas Republican Party echoed that sentiment, and framed Gates’ margin of victory as a signal that voters rejected the policies supported by national Democrats and Beto O’Rourke, the former Senate and presidential candidate who campaigned avidly for Markowitz.

Austin Chambers, president of the Republican State Leadership Committee, which supports Republican legislative candidates around the country, released a statement quoting several Democrats who suggested in recent weeks that the race would serve as a preview for 2020.

“Democrats everywhere said this Texas election was a ‘bellwether’ — and that it would set the tone for the entire 2020 election cycle,” Chambers said. “Spoiler alert: they’re right, it was — just not with the outcome Democrats hoped for.”

In a Facebook Live broadcast Tuesday evening, O’Rourke downplayed the result, urging viewers to “keep your eyes on the prize,” a nod toward the November elections.

In the special election runoff for House District 148, Democrat Anna Eastman led Republican Luis LaRotta with more than 65 percent of the vote and 100 percent of voting centers reporting. The dark-blue Harris County district historically has elected Democrats.

Eastman, a former HISD trustee, will succeed Democrat Jessica Farrar. She retired last year after a 25-year tenure representing House District 148, which covers area north of downtown and part of the Heights, extending northwest outside Loop 610.

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House District 28, meanwhile, covers a swath of Fort Bend County from Katy to Rosenberg and Simonton to Mission Bend. Zerwas stepped down last year rather than seek an eighth term.

In a statement, Texas Democratic Party Chairman Gilberto Hinojosa said the race “will be a toss-up in November,” when Markowitz will appear on the ballot again. She is unopposed in the March Democratic primary, while Gates faces one Republican opponent.

Meanwhile, Eastman now faces four Democratic primary opponents for the chance to again face LaRotta, who is unopposed on the Republican primary.

Renée Cross, senior director of the Hobby School of Public Affairs, said Democrats overreached in painting the Fort Bend district as a bellwether and cast doubt on whether the result serves as an accurate forecast of the November 2020 results.

“I think the Democrats to a certain extent shot themselves in the foot with that because the expectations were so high,” she said. “If you look at voting history for the last 10 years, to think they were just going to flip this seat in a special election in January after we had so many elections the last few months, that was really reaching.”

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The results Tuesday night mean Democrats will need to net nine seats in 2020 to take control of the lower chamber.

Despite Gates’ resounding victory, Hinojosa said Markowitz forced Republicans to “spend millions of dollars in a district that has never been historically competitive.” Gates, who runs a property management company, spent more than $1 million of his own money on the race, helping counter the Democrats’ outside help.

For her part, Markowitz turned to the general election.

“We knew this election would be tough — it’s not easy to take on Republicans in an off-year special election, but we made this seat competitive in a way it’s never been before. We head into November having established a movement for change and that movement will continue across the state of Texas through November.”

The two elections saw a wide disparity in turnout: More than 30,000 voters turned out for the House District 28 contest, easily surpassing the prior special election runoff record of nearly 22,000 votes. In House District 148, nearly 7,000 voters turned out.

jasper.scherer@chron.com