The best-selling author Michael Wolff is suing Melania Trump in an unprecedented court case—after she threatened to sue him for $1 billion. The author, who is co-host of The Daily Beast’s hit podcast, Inside Trump’s Head, is accusing the First Lady of launching an assault on his free speech and trying to stifle “legitimate inquiry” into Jeffrey Epstein. The case is the first time Melania Trump has been sued as First Lady and appears to be the first time a president’s wife has been the subject of court action. Wolff is asking the court for permission to question Melania and Donald Trump under oath about their dealings with Epstein...