Last month, when President Donald Trump toured a Boeing aircraft plant in North Charleston, South Carolina, he saw a familiar face in the crowd that greeted him: Patrick Caddell, a former Democratic political operative and pollster who, for forty-five years, has been prodding insurgent Presidential candidates to attack the Washington establishment. Caddell, who lives in Charleston, is perhaps best known for helping Jimmy Carter win the 1976 Presidential race. He is also remembered for having collaborated with his friend Warren Beatty on the 1998 satire “Bulworth.” In that film, a kamikaze candidate abandons the usual talking points and excoriates both the major political parties and the media; voters love his unconventionality, and he becomes improbably popular. If the plot sounds familiar, there’s a reason: in recent years, Caddell has offered political advice to Trump. He has not worked directly for the President, but at least as far back as 2013 he has been a contractor for one of Trump’s biggest financial backers: Robert Mercer, a reclusive Long Island hedge-fund manager, who has become a major force behind the Trump Presidency.