HUNTSVILLE, Ala. — President Donald Trump says National Football League owners should fire players who kneel during the national anthem. And he’s encouraging spectators to walk out in protest. In an extended riff during a freewheeling rally speech in Alabama Friday night, Trump also bemoaned that football games have become less violent. “They’re ruining the game,” he complained. Several athletes, including NFL players, have refused to stand during “The Star-Spangled Banner” to protest of the treatment of blacks by police. Trump says those players are disrespecting the flag and deserve to lose their jobs. “That’s a total disrespect of our heritage.