(By David A. Martin, Warner-Booker Distinguished Professor Emeritus at the UVA School of Law) Early in his Sept. 5 press conference announcing the termination of DACA, Attorney General Jeff Sessions laid the groundwork this way: No greater good can be done for the overall health and well-being of our Republic than preserving and strengthening the impartial rule of law. … Societies where the rule of law is subject to political whims and personal biases tend to become societies afflicted by corruption, poverty, and human suffering. With these general propositions, I couldn’t agree more. But...