Rep. Joaquin Castro backs Cristina Tzintzún Ramirez in Democratic Senate race against John Cornyn

U.S. Rep. Joaquin Castro has endorsed Cristina Tzintzún Ramirez in the Democratic Senate race to challenge incumbent Republican John Cornyn.

“Texans deserve better than Sen. John Cornyn, who has spent years fighting against the rights of workers, women, immigrants, and so many others – all while claiming to represent the interests of Texans in DC,” Castro said in a news release. “To replace him, we need someone who understands the Texas of today and who has a positive vision for our future.”

Tzintzún Ramirez co-founded the Workers Defense Project, a group that has fought for the health and rights of construction workers. On her stump speech, she’s tried to contrast her activism against Cornyn’s record.

“While John Cornyn was accepting millions of dollars from the construction industry, which here in Texas in the largest employer of undocumented labor, I was making $43,000 a year representing tens of thousands of workers who built our state’s economy and lost their fingers, limbs and lives in the process,” she said at a Plano event.

Tzintzún Ramirez is in a tight, 12-person race for Senate. Polls show no candidate has broken from the field. The top contenders include former Air Force helicopter pilot MJ Hegar of Round Rock, state Sen. Royce West of Dallas, former Houston council member Amanda Edwards and former U.S. Rep. Chris Bell of Houston.

Last year Democrats tried to coax Castro, or his brother, former Housing Secretary Julián Castro, into the Senate race. Julián Castro was a presidential contender and Joaquin Castro opted to remain in the House.

“I have a tremendous amount of respect for each of our Democratic candidates in this race, but with her extensive track-record working on behalf of Texans to secure living wages, protect immigrant communities, and engage our young and diverse electorate, I’m proud to support Cristina Tzintzún Ramirez,” Castro said.

Tzintzún Ramirez is also backed by Castro’s mother, civil rights activist Rosie Castro. The support from the Castro family could help Tzintzún Ramirez win Hispanic voters that are influential in Democratic Party primaries.

Last year Tzintzún Ramirez apologized for saying that part of her surname, Tzintzún, is “more Mexican than any Garcia or Lope,” adding that “we were the only indigenous group in Mexico that were not defeated by the Aztecs. So you know I come from good lineage and I’m ready to defeat John Cornyn.”

The remark caused an uproar on social media after appearing in a profile of her in The Dallas Morning News.

Tzintzún Ramirez is hoping to get the lion’s share of Hispanic votes in the March 3 primary. Early voting begins Tuesday.

She called Castro a “tireless advocate for all Texans.”

“I look forward to working together towards a brighter future for Texas,” Tzintzún Ramirez said in a statement.