In the past few days, the calls for a special counsel to look into the FBI and Justice Department have grown louder. Sens. Chuck Grassley and Lindsey Graham want one. So do Reps. Bob Goodlatte, Mark Meadows, Jim Jordan and others. Attorney General Jeff Sessions is thinking about it. Meanwhile, President Trump's deputy press secretary has told reporters that the president's lawyers want one too.

It's a tempting proposition. Republicans are plagued by a special counsel whose mere existence calls into question the legitimacy of the last election. Why shouldn't they inflict the same menace on Mr. Trump's opponents? The answer is that a special counsel is not only unnecessary but counterproductive.