Don’t try to impeach your opponent without legal cause. No one following the Russian-collusion and related dramas should be in any doubt about the steady flow of the balance of damaging evidence away from Trump and on to his accusers. It is clear that the hierarchy of the FBI and analogues in the Justice Department and intelligence services, horrified at the thought of a Trump victory though confident it would not occur, took liberties — in the soft treatment of Hillary Clinton’s email and uranium problems, and in abetting the Clinton campaign’s effort to smear Trump with the Russian-collusion argument....