A top advisor to Zohran Mamdani's New York City mayoral campaign reportedly helped launch the re-election bid of the House of Representatives' chief progressive.Morris Katz, a left-wing political operative who serves as the Mamdani campaign's lead media strategist, helped create a new ad for Congressional Progressive Caucus Chair and "Squad" member Greg Casar, D-Texas, announcing his 2026 midterm campaign on Monday morning, Politico Playbook reported.Katz is no stranger to Democratic campaigns, having helped "fortify and expand" New York's Working Families Party, according to an online biography, and most recently creating ads for a Democrat in Maine who is challenging longtime Sen. Susan Collins, D-Maine. He also advised Dan Osborn's independent Senate campaign in Nebraska.The Fight Agency, where he works creating ads and advising on campaign strategy, has rolled out videos for Sens. John Fetterman, D-Pa., and Bernie Sanders, I-Vt., among others.CUOMO, ADAMS TRADE SHOTS OVER WHO SHOULD DROP OUT IN RACE AGAINST MAMDANI FOR NYC MAYORBut it's his work for Mamdani that propelled Katz's name to the national stage.He told New York Magazine in June that he was taken with the 33-year-old democratic socialist after their first meeting."I left thinking, I love this man. And I am supposed to be skeptical. What is going to happen when the rest of New York gets to know him?" the outlet published him saying.Katz is now reportedly throwing his progressive ad-making chops behind Casar, who is running for his third term representing part of the Austin, Texas area.Fox News Digital reached out to the Fight Agency and Casar's campaign multiple times for confirmation and further comment but did not receive a response.Casar's new ad, which runs just over two minutes long, touts his time as a labor organizer and state lawmaker before coming to Congress in January 2023."Donald Trump and Greg Abbot don't want a guy like me in Congress, because I didn't start my career in the courtroom or the C-Suite. I started it here, on Austin construction sites, as a labor organizer fighting alongside workers to win a raise, a union, and the right to a water break," Casar says in the opening of the ad.He goes on to tout "taking on Trump, his billionaire buddies, and their puppet politicians," while the ad features images of other progressive darlings like Sanders and Rep. Alexandria Ocasio-Cortez, D-N.Y.The Fight Agency's website also features a brief ad promoting Casar's first House bid in 2022.MEET MAMDANI'S RADICAL ADVISORY CIRCLE THAT INCLUDES COMMUNIST ACTIVIST, ANTI-ISRAEL ADVOCATESThe timing of Casar's announcement is significant; it comes days after Texas' state legislature passed new congressional maps backed by the White House which could give Republicans as many as five new seats in the House of Representatives.It's triggered a redistricting war across the country and already pitted Democratic lawmakers against each other.Rep. Lloyd Doggett, D-Texas, a longtime House lawmaker who would have had to face Casar in a primary under the new maps, announced last week he would not run for re-election if the new district lines went into effect.CLICK HERE TO GET THE FOX NEWS APP"I had hoped that my commitment to reelection under any circumstances would encourage Congressman Casar to not surrender his winnable district to Trump," Doggett said in a statement on Thursday. "While his apparent decision is most unfortunate, I prefer to devote the coming months to fighting Trump tyranny and serving Austin rather than waging a struggle with fellow Democrats.If Trump's extreme gerrymandering prevails, I wish Congressman Casar the best."Casar said Thursday in response, "Lloyd Doggett is an Austin institution. Ive learned so much from him. Im grateful to him. The fight for democracy continues."He wrote on X Monday morning of his decision to switch districts, "I'll keep fighting Trump's gerrymander. If the new maps hold, Im running in the new Austin District (37), which includes my home, my city council district, and 250,000 of my current constituents."