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"Squad"-backed Texas Democrat Jessica Cisneros on Thursday announced that she will again run against Rep. Henry Cuellar in a primary, teeing up yet another battle between the moderate wing of the Democratic Party and its most progressive members.

Cisneros fell just short in her effort to unseat Cuellar, D-Texas, last year, despite backing from "Squad" Reps. Alexandria Ocasio-Cortez, D-N.Y., and Ayanna Pressley, D-Mass., as well as former presidential candidate Sen. Elizabeth Warren, D-Mass. 

Cuellar emphasizes his moderate streak in Congress. He's been unafraid to criticize the Biden administration over its immigration policy and recently appeared at a lengthy press conference with Sen. Lindsey Graham, R-S.C., on the issue. Cisneros attacked the incumbent over that reputation in her campaign announcement video Thursday

"What's Henry Cuellar done in the last year since he got reelected?" Cisneros said. "He introduced anti-immigration bills with Republicans to further separate families. He was the only Democrat to vote in favor of corporate interests over protecting workers and strengthening unions. And he brought unusable, defective COVID-19 tests into Laredo." 

Democrat Jessica Cisneros, who is campaigning for a House seat, participates in the Citrus Parade to introduce herself to the attendees in Mission, Texas, Jan. 25, 2020. (REUTERS/Veronica Cardenas) (REUTERS/Veronica Cardenas)

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"South Texas deserves are representative that's going to fight for our dreams as hard as we do. For ‘Medicare-for-All,’ so families don't have to go to Mexico to afford basic health care," Cisneros continued. "For immigrants' rights, because we don't want a wall or policies that tear our South Texas community apart. For reproductive health care [because our mothers, our daughters, our sisters] our friends and family deserve freedom, dignity and respect." 

Cuellar's campaign, meanwhile, attacked Cisneros as a "socialist" and touted the congressman's record. 

"South Texans have already rejected the Socialist Cisneros despite the hundreds of thousands of dollars in dark money that fueled her campaign," Cuellar campaign spokesman Colin Strother said. "She has never accomplished anything and believes that she can build successful campaign built on lies and false personal attacks. Congressman Cuellar is widely respected by members on both sides of the aisle and has an unmatched record of producing results for his district."

Justice Democrats, the political action committee that played a major role in Ocasio-Cortez's first election as well as the elections of freshman "Squad" members Reps. Cori Bush, D-Mo., and Jamaal Bowman, D-N.Y., announced it is yet again backing Cisneros Thursday. 

Rep. Henry Cuellar, D-Texas, delivers remarks during a rally for the passage of the USMCA trade agreement, on Sept. 12, 2019, in Washington, D.C. (Photo by Tom Brenner/Getty Images) (Getty Images)

"We are so proud to support @JCisnerosTX," the group tweeted. "Together, we are ready to finish what we started and bring a new generation of leadership to South Texas."

Justice Democrats' Twitter header was already a photo of Cisneros Thursday morning. 

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Cisneros' announcement comes on the heels of a big blow for Democrats' progressive wing on Tuesday. Cuyahoga County councilwoman Shontel Brown defeated former state Sen. Nina Turner in the Democratic congressional primary in Ohio’s 11th District. Turner was backed by Sen. Bernie Sanders, I-Vt., and Ocasio-Cortez. 

The victorious Brown, meanwhile, was supported by 2016 Democratic presidential nominee Hillary Clinton and the Congressional Black Caucus. 

Representatives for Cuellar did not immediately respond to a request for comment from Fox News. 

Fox News' Paul Steinhauser contributed to this report.