Democrat Eliz Markowitz suffered a major loss in Tuesday's special runoff election for Texas House District 28, despite a flood of support from liberal groups and top Democrats like Beto O'Rourke.

Republican Gary Gates beat Markowitz by 16 points in the suburban Houston race Democrats hoped would be a bellwether for flipping the state House to Democratic control. Markowitz badly underperformed O'Rourke, who lost the district by three points in 2018 to Sen. Ted Cruz (R., Texas), and even Hillary Clinton, who lost it by 10 points in 2016 to President Donald Trump.

O'Rourke campaigned heavily for Markowitz, making it his "second home" over the past month. The race was an early test of his political strength following his disappointing 2020 presidential campaign, which he suspended in November.

His new political action committee, Powered by People, founded in an effort to turn the Texas legislature blue, brought 1,000 people to the district to help in the contest. Outside liberal groups such as Planned Parenthood of Greater Texas, Moms Demand Action, and EMILY’s List endorsed Markowitz and poured hundreds of thousands of dollars into the race.

2020 hopeful Michael Bloomberg stumped alongside Markowitz in December, and she also received endorsements from Joe Biden and Sen. Elizabeth Warren (D., Mass.). Former presidential candidate Julián Castro campaigned for her as well.

"Guess what? This will set the tone for the entire general election in 2020," Biden said in a video alongside Markowitz on Jan. 16.

O'Rourke congratulated Gates Wednesday morning and looked ahead to November when the two candidates will likely have a rematch during the general election.

So proud of @ElizMarkowitz, her team and all of the amazing volunteers who produced one of the highest turnouts in a special election in Texas history. The work continues, building for victories in November in this and other state house races. Congratulations to @GatesforTexas — Beto O'Rourke (@BetoORourke) January 29, 2020

Gates, a businessman who spent $1.5 million of his own money on the contest, told supporters Tuesday, "[Democrats] thought this was a seat they could flip," prompting responses of "No way" and "Don't mess with Texas," the Texas Tribune reported.

Texas governor Greg Abbott (R.) mocked O'Rourke over the result, tweeting "Beto math doesn't work" while pointing out how much Gates outperformed Cruz's margin in the district in 2018.

Wait. Beto math was that if he won or was close in a House district then he could help a democrat win. He came within 3% in this district. Early returns show the Republican winning by about 18% Beto math doesn’t work.

All of that $ was incinerated. https://t.co/1euLaqE0px — Greg Abbott (@GregAbbott_TX) January 29, 2020

O'Rourke's narrow loss in the 2018 Senate race made him a national Democratic star, which he used as a launching pad for his 2020 presidential campaign. However, the former three-term congressman couldn't gain traction, even with swings to the left like his call for a confiscation of AK-47 and AR-15 rifles.

The Austin American-Statesman reported GOP polling found O'Rourke to be unpopular in District 28 and his deep involvement "may have proved a mixed blessing at best."