The Texas Democratic Party announced the results of a recount in the race on Tuesday, which found Cuellar ahead by 289 votes.
Cisneros, who also lost to Cuellar in 2020, conceded on Tuesday, according to a release from her campaign.
“We always knew this was an uphill battle. We were up against a corrupt political machine, Republican-funded Super PACs, the Koch brothers, private prisons, Big Oil, the Chamber of Commerce, dark money groups, Big Pharma, and nearly the entire Democratic Party establishment in Washington – and we still refused to back down,” Cisneros said in a statement.
“With this close of a margin, it’s clear that without their aggressive interference in the lives of South Texas families, we would have won.”
The result is a blow to progressives and, more broadly, Democrats who support abortion rights and hope that anger over the Supreme Court’s draft opinion that would strike down Roe v. Wade might drive the issue to the forefront this election cycle.
Despite being hammered over his anti-abortion position by Cisneros and her allies, including EMILY’s List, which invested big late in the race, Cuellar again emerged with the nomination in the South Texas district, which runs south from San Antonio to the US-Mexico border.
Cuellar, like other Democratic moderates during this year’s primaries, benefited from a surge of outside money and the backing of party leaders in Washington. House Speaker Nancy Pelosi, Majority Leader Steny Hoyer and Majority Whip James Clyburn, who traveled to Texas to campaign for Cuellar, all stood with the congressman despite frustration from pro-abortion rights voters.
This story has been updated with additional information.