Twitter / @JCisnerosTX

Jessica Cisneros (right) speaks to potential voters on the University of Texas Rio Grande Valley campus.

Jessica Cisneros, a 26-year-old immigration attorney from Laredo, outraised rival U.S. Rep. Henry Cuellar as she challenges the longtime congressman in the upcoming Democratic primary, the Express-News reports Cisneros banked more than $350,000 in contributions for the first six weeks of the year — some coming from celebrity backers such as actress Susan Sarandon. That compares to Cuellar's $100,000 take during the period. The incumbent still has more than $2 million in his war chest, compared to Cisneros' $296,000.The fundraising details come as the Texas Tribune reports U.S. House Speaker Nancy Pelosi visited Laredo over the weekend, delivering a pep talk to staffers and volunteers at Cuellar's headquarters.The race is shaping up to be a key battleground between the Democratic party's progressive and centrist wings.Cisneros is backed by Justice Democrats, the insurgent progressive group behind freshman U.S. Rep. Alexandria Ocasio-Cortez, D-New York. Meanwhile, moderate Cuellar has racked up endorsements from establishment Dems plus the pro-businesses U.S. Chamber of Commerce and the political network formed by the Koch brothers.The traditionally Democratic-leaning House District 28 stretches from South San Antonio down to Laredo.