Some conservative commentators have applauded Donald Trump for challenging President Barack Obama on his birth certificate. Conservative author Ann Coulter isn’t one of them. On Monday night’s “Hannity” on the Fox News Channel, Coulter said the “birther” conspiracy has been long debunked by other conservative outlets. “Well, I think maybe I’ve been watching too much Charlie Sheen because Donald Trump seems perfectly sane to me,” Coulter said. “I don’t know where he gets this $2 million Obama has spent to keep his birth certificate — he posted his birth certificate on his web page. I am glad that Donald Trump...