U.S. Rep. Alexandria Ocasio-Cortez, D-N.Y., is endorsing Cristina Tzintzún Ramirez in the huge primary to take on U.S. Sen. John Cornyn, R-Texas, less than two weeks before election day.

Tzintzún Ramirez, a progressive organizer, was one of seven federal candidates nationwide whom Ocasio-Cortez endorsed Friday through her Courage to Change political action committee. Tzintzún Ramirez was the only U.S. Senate contender.

"It’s important for us to create mechanisms of support because so much of what is happening in Washington is driven by fear of loss," Ocasio-Cortez told The New York Times, which first reported the endorsements. "We can really create an ecosystem that makes people more comfortable into making the leap to make politically courageous choices.”

Tzintzún Ramirez welcomed the endorsement in a statement, promising to "fight for the bold, progressive change that Texans deserve."

She is among 12 candidates competing in the March 3 primary to take on Cornyn, a primary that is almost certain to go to a runoff. Her primary rivals include MJ Hegar, who has the backing of the Democratic Senatorial Campaign Committee.

While Hegar, a former Air Force helicopter pilot, is the top fundraiser in the primary and has accrued the most national support, Tzintzún Ramirez has built momentum as the progressive alternative to Hegar. Earlier this week, Tzintzún Ramirez won the support of U.S. Rep. Joaquin Castro of San Antonio.

Even before Friday, Cornyn's campaign had been deriding Tzintzún Ramirez as "AOCristina."

"AOC’s endorsement of AOCristina proves that radical Liberals are coming for Texas with all they’ve got," Cornyn campaign manager John Jackson said in a statement. "Cristina Tzintzún Ramirez’s policies are out of step with Texas voters and we look forward to educating Texans on her disastrous Green New Deal, Medicare-for-None, and gun seizure program this Fall."

In response to Ocasio-Cortez's endorsement, Hegar's campaign provided a statement touting her bid that said, "Texans are going to vote for someone who is outside the political system and embodies Texas values of strength, courage, and independence." The campaign of another one of Tzintzún Ramirez's primary rivals, Chris Bell, was more critical of the endorsement, calling it "just another example of an outsider with views from the fringe of our party trying to tell Texans how to vote."

Ocasio-Cortez's PAC endorsements Friday also included Jessica Cisneros, the primary challenger to Laredo U.S. Rep. Henry Cuellar. Ocasio-Cortez herself endorsed Cisneros in October.