Andrew Koppelman and Steven Lubet write for CNN Opinion, “Rep. Jason Chaffetz has some explaining to do. As chairman of the House Committee on Oversight and Government Reform, the Utah Republican spared no effort in leading the multiple investigations of Hillary Clinton. Yet he has shown little interest in investigating, or even questioning, President Donald Trump’s myriad financial entanglements. His explanations of the difference suggest that Chaffetz doesn’t even understand why Congress has the power to investigate in the first place.”