Rep. Henry Cuellar, Democratic congressman from the 28th district in Texas, leads primary challenger Jessica Cisneros by just 177 votes in their runoff contest after ballots were counted on Tuesday.

Cuellar, who has served in Congress since 2005, declared victory early Wednesday morning.

"Tonight, the 28th Congressional District spoke, and we witnessed our great Democratic system at work," a confident Cuellar said in a statement. "The results are in, all the votes have been tallied -- I am honored to have once again been re-elected as the Democratic Nominee for Congress."

The left-leaning Cisneros, however, was not ready to concede.

PRIMARY ELECTIONS IN GEORGIA, ALABAMA, RUNOFF IN TEXAS

"This election is still too close to call, and we are still waiting for every ballot and eligible vote to be counted," Cisneros tweeted. "This fight isn't over."

For now, Cisneros is correct, as mail-in ballots that were postmarked by Tuesday can still be counted if they are delivered to county officials by 5 p.m. Wednesday. Additionally, the miniscule margin means Cisneros can petition for a recount.

The incumbent Cuellar told reporters he is ready.

DEMS CUELLAR, CISNEROS HEAD TO RUNOFF IN TEXAS US HOUSE PRIMARY

"I know what it is to do a recount in an election contest," he said, according to the Texas Tribune. "We have very good attorneys and if we need to, we will defend our election victory."

Cuellar himself used a recount to take office in the first place. After he trailed by less than 150 votes to incumbent Ciro Rodriguez in 2004, and after a recount he won by 58 votes. 

The runoff contest between Rep. Henry Cuellar and Democratic primary challenger Jessica Cisneros appears destined for a recount

Jessica Cisneros meets her opponent, U.S. Rep. Henry Cuellar, for the first time on the campaign trail at the Citrus Parade in Mission, Texas, Jan. 25, 2020. (Reuters/Veronica Cardenas)

The race between Cuellar and Cisneros gained attention after a leaked draft of a Supreme Court opinion called for Roe v. Wade to be overruled, placing abortion rights in the hands of individual states rather than having the practice recognized as a constitutional right.

Cuellar is the sole House Democrat who is pro-life, and others in his party have gone after him over this. He has also received a positive rating from the National Rifle Association, although in recent years he has called for a stronger background check system for gun purchases.

Rep. Alexandria Ocasio-Cortez, D-N.Y., blasted the Democratic establishment for supporting Cuellar in spite of these positions, especially given the concern over abortion rights and Tuesday's school shooting in Cuellar's home state of Texas.

"On the day of a mass shooting and weeks after news of Roe, Democratic Party leadership rallied for a pro-NRA, anti-choice incumbent under investigation in a close primary," Ocasio-Cortez tweeted. "Robocalls, fundraisers, all of it. Accountability isn’t partisan. This was an utter failure of leadership."

She added: "Congress should not be an incumbent protection racket and sadly it is treated as such by far too many."

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The investigation Ocasio-Cortez referenced involved the FBI raiding Cuellar's home and office earlier this year. Cuellar's attorney told Fox News that the Justice Department assured Cuellar that he was not the target of the investigation.

Cuellar previously defeated Cisneros in a close contest in the 2020 Democratic primary.