The FBI has been investigating Clinton for months--but an even more secretive Federal agency has its own important beef with her. For a year now, Hillary Clinton's misuse of email during her tenure as Secretary of State has hung like a dark cloud over her presidential campaign. As I told you months ago, EmailGate isn't going away, despite the best efforts of Team Clinton to make it disappear. Instead, the scandal has gotten worse, with never-ending revelations of apparent misconduct by Ms. Clinton and her staff. At this point, EmailGate may be the only thing standing between Hillary and the...