There are two big questions about the now-completed investigation into President Trump, and the answers will determine what happens next. First, why did special counsel Robert S. Mueller III not render a judgment on whether Trump had obstructed justice? And second, since Attorney General William P. Barr did render such a judgment, why isn’t that the end of the matter?

The public appearances last week of Mueller and Barr answer both questions. We saw a hyper-careful special counsel who bent over backward to be fair to Trump. And we saw an attorney general who was acting as the president’s personal lawyer, not the lawyer for the American people.

Mueller explained in his news conference that he would not answer the obstruction question, just as his report didn’t answer the question except to say he could not clear Trump because the facts would not permit him to. Justice Department guidance held that he could not indict a sitting president, he said, so he did not reach a conclusion as to whether the president committed crimes. He said it would be unfair to attack someone as a criminal without indicting them because there would be no legal process for them to prove the accusations wrong. That didn’t mean Mueller was acting as some “angry Democrat” (a hard thing for a Republican to do, in any event) — it meant he was being careful to protect Trump’s rights.

Barr, by contrast, took the opposite approach. He appeared the next day on CBS News and said, “I personally felt he could’ve reached a decision,” and that “the opinion says you cannot indict a president while he is in office, but he could’ve reached a decision as to whether it was criminal activity.”

Barr’s statement was news, not only to the American public, but also, I suspect, to Mueller himself. It also should have come as news to someone else: William P. Barr. On the first day of his confirmation hearing nearly five months ago, Barr was asked by Sen. John Cornyn (R-Tex.) about former FBI director James B. Comey’s July 2016 news conference on the decision not to indict Hillary Clinton over her use of a private email server while secretary of state.

Here is what Barr said in January: “I thought that to the extent [Comey] actually announced a decision was wrong, and the other thing is, if you’re not going to indict someone, then you don’t stand up there and unload negative information about the person. That’s not the way the Department of Justice does business.”

Barr has now directly contradicted what he told the Senate. Why?

The answer has to do with how Barr backed himself into a corner when he cleared Trump of obstruction of justice. Barr was criticized resoundingly for reaching such a determination within 48 hours of receiving Mueller’s report (which was more than 400 pages long). Barr tried to defend himself by explaining that he had had time to evaluate everything because Mueller had told him in a meeting three weeks beforehand that he wasn’t going to reach a decision on obstruction of justice. This has always been a strange claim — that Barr was evaluating the evidence without the report in his hand — but now it gets absurd.

If Barr thought Mueller could have reached a decision on obstruction of justice, did he tell Mueller that when they met in March? Wouldn’t that have literally been Barr’s job, as the supervisor of the special counsel? Instead, he revealed his views only later — and contradicted his earlier position that prosecutors cannot “unload negative information about a person” and that that is not how the “Department of Justice does business.”

Barr’s position, as he described it on CBS, is absurd on its face. Imagine the outcry if Mueller were to have done what Barr now claims he could have done: Mueller would be labeling Trump a criminal, but Trump would have no legal process to defend himself. Folks — including me — would scream about the unfairness of such an outcome. Mueller was faithful to long-standing Justice Department considerations about being fair to potential defendants; Barr, by contrast, appears to be lurching from one bad position to the next.

Barr has thrown himself in with Trump in ways unbecoming to the nation’s highest legal official. His conduct in trying to clear Trump is of a piece with his baseless attacks on “spying” by the FBI and his defiance of Congress’s subpoenas. The president already has a White House counsel, who defends the institution of the presidency, as well as a private legal team. Unlike other Cabinet officers at the founding who were susceptible to direct presidential control, the attorney general has been understood to serve the interests of the law, not of the president who put him there. But right now, U.S. taxpayers who pay Barr’s salary are also funding Trump’s legal defense team, and they lack a government official who represents them.

The only way forward is for Congress to carry out a thorough investigation and reach its own conclusions. Call it an impeachment inquiry if you wish; nothing turns on the name. But a Congress that spent years investigating Benghazi surely should spend an equivalent amount of time and energy investigating potential wrongdoing by the president of the United States. Trump and Barr both insist that he has been cleared, but that’s not what more than 1,000 former federal prosecutors who read the Mueller report say: The evidence described in the report would lead to an indictment of anyone else in the country. If that’s right, we simply cannot have a president who remains in office because of a technicality. If that’s wrong, then let’s get the answer and give Trump an opportunity to clear his name.

Barr’s attempt to clear the president is meaningless. It makes him look willing to say anything and do anything to protect his boss. If Barr wants to keep defending Trump, he should take a page from one of his predecessors, Henry Stanbery, who stepped down as attorney general to serve as President Andrew Johnson’s impeachment counsel. Stanbery, notably, tried to come back as attorney general after the impeachment proceedings concluded. The Senate did not confirm him.

The American people deserve an answer about whether the president obstructed justice. Mueller did not answer that question. Barr tried to. While ordinarily the word of an attorney general should carry much weight, it is difficult, if not impossible, to extend those norms to this situation. Barr has shown himself to be an unreliable and unsteady voice, careening from one position to the next, always in favor of protecting his boss. And even had Barr acted without such partisanship, the whole point of the idea that a sitting president cannot be indicted is that there is an alternative forum to review those questions.

Mueller, pointedly, noted in his news conference last week that the Justice Department opinion barring the indictment of a sitting president says that “the Constitution requires a process other than the criminal justice system to formally accuse a sitting president of wrongdoing.” Everyone knew what other process Mueller meant. Congress is going to have to provide the answers.

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