Democratic state Senator John Whitmire emerged victorious in Houston's closely-watched mayoral race, defeating Democratic U.S. Representative Sheila Jackson Lee. According to the Associated Press, Whitmire secured a resounding lead of 65.27% to 34.73% over Jackson Lee. The mayoral runoff election took place on Saturday, December 9th, with early voting ending on December 5th. However, an advertisement for Jackson Lee erroneously urged voters to cast their ballots on or before December 7th, creating confusion among residents. Jackson Lee's office quickly pulled the ad, clarifying that it was created by an outside agency and not the campaign itself.

The mayoral race in Houston had been relatively lackluster, failing to capture voters' attention. Both candidates were Democrats, but Whitmire managed to secure support from Republicans, emphasizing his ability to work across party lines. In contrast, Jackson Lee struggled to expand her base of support beyond her strong backing from Democrats and Black voters. A University of Houston poll conducted in mid-November showed Whitmire leading Jackson Lee by 42% to 35%.

Despite endorsements from prominent Democrats, including Hillary Clinton and Nancy Pelosi, Jackson Lee was unable to gain momentum. Whitmire, on the other hand, garnered support from local figures such as Jim “Mattress Mack” McIngvale and former Houston City Councilman Jack Christie, who ran as a Republican in the initial round of voting. Recognizing the importance of winning a diverse coalition of voters in Houston, Whitmire also courted the Latino vote, which makes up approximately 45% of the city's population. The University of Houston poll revealed Whitmire with a 20-point advantage among Latino voters.

Crime was a major issue in the mayoral race, with both candidates vowing to retain Police Chief Troy Finner. Whitmire focused his campaign on public safety, a strategy that has proven successful for moderate Democrats in other large cities. Attacking Jackson Lee as unsupportive of the police, outside groups flooded mailboxes with flyers criticizing her. Despite crime rates declining from their post-pandemic peak, Whitmire argued that they remained too high and instilled fear in Houstonians. He pledged to collaborate with Republican Governor Greg Abbott to deploy state troopers for patrols in the city.

Reaching the runoff election, Jackson Lee faced high unfavorability ratings. An October poll from the University of Houston's Hobby School showed that 43% of respondents would never vote for her, compared to 15% for Whitmire. In the same poll, 41% had a "very unfavorable" view of Jackson Lee, while only 28% had a "very favorable" view. Whitmire, however, faced allegations of conflicts of interest as a state senator. The Houston Chronicle reported accusations of blurring the line between public and private roles. Whitmire maintained that conflicts of interest were inevitable due to the low salary and part-time nature of the Texas Legislature, where members earn $7,200 a year.

Houston, as America's most diverse large city, presented a unique challenge for both candidates. Turner's victory in the 2015 mayoral race was largely attributed to support from Black voters and successful get-out-the-vote efforts. Jackson Lee aimed to galvanize Black voters but struggled to replicate Turner's success. The precincts with high numbers of Black voters saw significantly lower turnout.

Ultimately, Whitmire's broad coalition of support, including Republicans, moderate white Democrats, Hispanic voters, and Asian voters, propelled him to victory. Houston's election marked the last major race of 2023, with Whitmire assuming the mayoral office in America's fourth-largest city.