Right-wing Democratic Rep. Henry Cuellar is continuing to refuse to debate his primary challenger, progressive lawyer Jessica Cisneros, despite calls to do so from around the country as Cisneros continues to rack up endorsements from state and national figures and groups. 

Cuellar, a Democrat from south Texas, has dismissed Cisneros as an unserious candidate.

"Our people are waiting, Rep. Cuellar," Cisneros tweeted on Sunday. "Debate me."

The 240,000-member Texas AFL/CIO announced their support for Cisneros on Sunday. The endorsement is a major coup for the primary challenger.

In a video announcing the endorsement, Texas AFL-CIO President Rick Levy praised Cisneros' priorities and campaign. 

"The 240,000 members of the Texas AFL-CIO stated that we are going to stand proudly with Jessica Cisneros in her race for Congress," Levy said. "This district needs someone who is going to stand up for working people, stand up for poor people, and stand up for justice."

The backing of the union is a big get, tweeted journalist Brendan O'Connor.

"Cisneros is an immigration attorney running against Henry Cuellar, a right-wing Democrat and one of the worst people in Congress in either party," said O'Connor, "extremely big deal for her to get the Texas AFL-CIO endorsement."

Ocasio-Cortez also gave Cisneros a shout-out.

"Gaining an endorsement this big in a primary like hers is almost unheard of," said the New York Democrat of Cisneros. "She's working it."

Cisneros announced her campaign in June. As Common Dreams has reported, the immigration and human rights lawyer has been endorsed by popular national figures Rep. Alexandria Ocasio-Cortez (D-N.Y.) and Sen. Elizabeth Warren (D-Mass.). 

The raft of endorsements for Cisneros make clear that the time for her and Cuellar to debate is now, said Jamaal Bowman, himself a progressive primary challenger to Rep. Eliot Engel (D-N.Y.).

"Debate her," tweeted Bowman.

Cuellar spokesman Colin Strother did not respond to requests for comment. In an interview in June, Strother told Common Dreams that Cisneros was being directed by progressive group Justice Democrats and other "upper city special interest groups." 

"It's telling that my opponent is still refusing to debate me by claiming I'm 'not a serious candidate,'" Cisneros said in a statement Monday. "Yet here we are, a challenger raising over a million dollars and receiving the endorsement of the largest labor federation in the state—which he's failed to receive because he doesn't stand with our workers."