SAN ANTONIO — Just over 500 supporters of Jessica Cisneros flooded the Second Baptist Church in San Antonio Friday, where Vermont Sen. Bernie Sanders campaigned for the progressive upstart ahead of Tuesday's primary runoff election.

Sanders hopes Cisneros will add to the ranks of progressive lawmakers in Washington.

"Jessica understands that if we're going to rebuild the middle class in this country, we need to rebuild the trade union movement," Sanders said.

The event showcased Cisneros' strong union backing from the Texas AFL-CIO, which represents 235,000 members of the working class in Texas and focuses on "organizing change in Black and Hispanic communities."

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Jessica Cisneros watch party

Democrat Jessica Cisneros, who is campaigning for a House seat, speaks during her watch party in Laredo, Texas, March 3, 2020.  (REUTERS/Veronica Cardenas/File Photo)

The AFL-CIO kept the excitement high at the event. One supporter who introduced Cisneros said, "I've had two abortions and I'm proud of it." Another reminded the crowd that Cisneros, an immigration attorney, has a heart for the working class and immigrants because her parents are working-class immigrants.  

As she approached the stage, Cisneros supporters chanted her name, and she applauded them for forcing a runoff election against incumbent Rep. Henry Cuellar, whom she is challenging for the Democratic nomination for Congress this week. 

Cisneros recalled how working in Cuellar's office as a staffer inspired her determination to seek his congressional seat. 

Jessica Cisneros Henry Cuellar

Democrat Jessica Cisneros, who is campaigning for a House seat, greets her opponent, U.S. Rep. Henry Cuellar, D-Texas, for the first time on the campaign trail at the Citrus Parade in Mission, Texas, Jan. 25, 2020.  (REUTERS/Veronica Cardenas)

"It took me having to be in Congressman Cuellar's office to find out he was anti-labor, to find out he was anti-choice, to find out he had lobbyist after lobbyist go through his office and never host families that looked like me in Washington D.C. I even found out he was anti-immigrant," Cisneros said.

Cisneros recounted her struggles as an immigration attorney during the Trump era, and the crowd roared with excitement as she vowed those struggles would end if she wins.

Cisneros also has the backing of other left-wing Democrats in Congress, including Rep. Alexandria Ocasio-Cortez, D-N.Y. and other members of the progressive "Squad."

In his remarks Friday, Sanders addressed health care in America, housing and debt and boosted Cisneros' working-class credentials.

"Americans are paying the highest prices in the world for prescription drugs, and one of four Americans who get prescriptions from their doctors cannot afford to refill them," Sanders said. 

He declared a nationwide housing crisis and says millions of Americans cannot afford housing or college debt. 

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"Tens of millions of Americans leave college in debt and spend decades paying said debts, while others are too afraid to enter institutions because of college costs," Sanders said. "Jessica Cisneros is here to fight for the working class."

Bernie Sanders

Sen. Bernie Sanders, I-Vt., at the Capitol after the Senate conducted a procedural vote on the infrastructure bill July 21, 2021.  (Tom Williams/CQ-Roll Call, Inc via Getty Images)

The crowd flared with excitement again when Sanders said billionaires should not choose our leaders or buy elections. He also called the current federal minimum wage of $7.25 a starvation wage and said it must be boosted to $15. 

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The audience jumped to its feet when Sanders mentioned abortion, and the "threat" that Roe v. Wade will be overturned by the Supreme Court.

"Jessica is running against a candidate, Mr. Cuellar, who apparently believes it is appropriate for the government at the fed, state and local level to tell every single woman in this country what she can or cannot do with her own body. Jessica and I — and you — disagree," Sanders said. The crowd again chanted Cisneros' name.

Jessica Cisneros parade

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

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Abortion is a major issue in the Democratic primary race. Cuellar is the sole pro-life Democrat in Congress but still retains the backing of House Speaker Nancy Pelosi, D-Calif., and other party leaders. Cuellar voted against the Women's Health Protection Act, which would codify federal protections for abortion up to birth, when the House held a vote last year.