CHICAGO — America’s Communist Party concluded its national convention here seemingly united around two themes: that they are a significant ally of the increasingly powerful left-wing in the Democratic Party and that there remains a viable future for the party. As to the question of whether the CPUSA emerges in control or is instead absorbed into the broader socialism movement already peppering the platforms of Democrats running for president in 2020, officials expressed confidence the red star of their party will continue burning. But in the meantime, all goals should be subsumed by one: beating the dreaded President Donald Trump,...