The attorney general of the United States should not be influenced by the president or members of the White House staff on how to prosecute particular cases before the Department of Justice.


The department should have a healthy degree of separation from partisan and presidential politics.


That's not a matter of constitutional law. President Donald Trump is correct: The president has the authority to intervene.


But an independent Justice Department makes for a more fair and just Justice Department. This is a matter of wisdom gleaned from history.


It's better for the country to have a William Rogers than a John Mitchell and better to have a William Webster than a J. Edgar Hoover at the FBI.


This is not a question of law, but norm.


Justice should be blind, or as blind as possible, and not a matter of favoritism or partisanship.


When the attorney general recommended reduced punishment for Roger Stone, a onetime Trump friend convicted of perjury, witness tampering and obstruction in connection with the Russia probe, many questioned the judgment and motives of William Barr. Others said: Right or wrong, Mr. Barr is a straight shooter trying to do his job. He sincerely felt the department's recommended sentence of seven to nine years for Stone was excessive, that it should be less, and that the judge in the case should determine the appropriate amount of time served. Stone's sentencing is scheduled for today.


Enter Mr. Trump, with tweets criticizing the original sentencing recommendation and praising Mr. Barr for his revised recommendation. In an interview with ABC News, Mr. Barr said he had not made his recommendation based on a desire to please the president. He also said there had been no communication with the president on this matter. But he added that the president's tweets "make it impossible for me to do my job" and "I think it's time to stop the tweeting about Department of Justice criminal cases."


Mr. Barr reiterated his pledge not to be bullied by anyone — the press, members of Congress, the president or anyone else.


Mr. Barr is an honorable man and an independent AG. He has said that he considered resignation.


But he has himself made his life and work more difficult by wading into the culture wars. His October speech at the University of Notre Dame engaged topics such as abortion, gender identity and even welfare for single parents. It was an interesting speech that touched on the perils of moral relativism and secularism. But these subjects are not his business right now. Indeed, they are controversies a sitting AG should avoid.


The president, for his part, said he had a right to an opinion on Stone's case and that he uses social media to be heard. He pointed out that he'd chosen to steer clear of intervention and he expressed total confidence in Mr. Barr. He said: "I do make his job harder." In short, the president played his part as he sees fit and he feels Mr. Barr should play his role as he thinks best. And let the chips fall where they may.


All that is fair enough, as is the president's liberal use of the pardon power, exercised again this week. In the hands of a liberal president most pardons are considered acts of mercy and compassion.


But history shows that the president, the Department of Justice and the country are best served by a strong dose of detachment from partisanship at the department.


Past presidents who appointed family members, close friends, or campaign managers to lead the department have done us, and themselves, no favors.


The best AG in recent memory was Edward Hirsch Levi, the former University of Chicago president and law school dean, once called, by Robert Bork, "... as distinguished a man of the law as we shall know in our time." He was appointed by President Gerald Ford in 1975. He stayed out of the news and did his job, restoring faith and functionality to the Department of Justice.


Yes, Justice, justice and the country would be well served if both the president and the AG could better discipline their tongues.


Originally published by the Pittsburgh Post-Gazette. Distributed by Tribune Content Agency, LLC.