Article continues below advertisementSydney Sweeney and Zendaya - once close costars on HBO's Euphoria - are locked in one of Hollywood's most bitter new feuds, and insiders claim it all stems from their starkly opposing views on Donald Trump.Sweeney, 28, who plays Cassie Howard in the hit drama, has reportedly angered her former friend Zendaya, 29, by embracing her Republican leanings and refusing to distance herself from Trump's endorsement of her controversial American Eagle ad campaign.