Conservative columnist Ann Coulter tore into President Obama in an appearance on the Fox News Channel’s “Hannity” show Wednesday night, calling him a “feckless idiot” and charging that the U.S. is “retreating all over the world.” Coulter was especially outraged by the White House’s “pathetic” use of “hashtag diplomacy” on Twitter to raise awareness of the kidnapping of hundreds of girls by the Nigerian terrorist group Boko Haram.