WASHINGTON — President Trump on Tuesday lashed out at the Koch brothers, tweeting that the billionaire industrialists are a “total joke in real Republican circles” and that he is “a puppet for no one.” It’s the latest salvo between the president and Charles and David Koch, who did not endorse Trump in his 2016 presidential bid and have lashed out at Trump’s spending plans and trade policies. On Monday, the political advocacy network created by the billionaire industrialists announced it would not back the GOP candidate in the North Dakota Senate race.