Republican members of Congress defy Trump on legislation despite his primary endorsements against incumbent senators

Republican senators and representatives are increasingly willing to vote against Trump's agenda, particularly on foreign policy and spending measures, even as Trump endorses challengers to unseat incumbent Republicans in primaries. Sen. Bill Cassidy voted with Democrats on Iran war powers despite losing his primary to a Trump-backed candidate; Rep. Thomas Massie and others have similarly broken ranks. Senate Republicans express frustration that Trump's primary interventions are creating "free agents" willing to defy him at a moment when the party holds a narrow congressional majority.