SAN ANTONIO (KTSA News) –  Former San Antonio Mayor Julian Castro wasn’t off the presidential campaign trail for long. After announcing Monday his endorsement of Elizabeth Warren in her bid for the Democratic Presidential nomination, Castro has joined her in several campaign appearances.

With an audience of about 3,000 supporters at the Kings Theatre in Brooklyn, Castro walked on stage as Selena’s “Baila Esta Cumbia” played before he introduced Warren.

Warren also has been making the rounds on national television shows in hopes of boosting her campaign ahead of the Iowa caucuses. During an appearance on NBC’s Late Night with Seth Meyers, she talked about Castro’s endorsement.

“Julian and I have been friends for a long time because we fight for a lot of the same things,” Warren said. ” We feel like we’ve got this chance in 2020, this real chance to be able to build an America that works for everybody and Julian is just a great partner in this great fight.”

Meyers pounced on the word “partner” and asked what many people have been speculating about since Castro announced his endorsement for Warren.

“Now you mentioned partner. Anytime anyone endorses someone else , they go ‘oh, potential running mate’ What do you have to say?” asked Meyers.

Warren responded, “It’s way too presumptuous.”

Warren also was asked what she thinks about actress Kate McKinnon’s portrayal of her on “Saturday Night Live.”

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