On Wednesday, Attorney General Jeff Sessions will appear before the Senate Judiciary Committee for the first time since his confirmation hearing in January. To say his tenure since taking office has been rocky would be an understatement. In the past nine months, Sessions has been accused of lying under oath to Congress about meetings with Russian officials during last year’s presidential campaign; forced to recuse himself from the Justice Department’s Russia investigation; rebuked for belittling a federal judge over the president’s travel ban; publicly attacked and humiliated by the president; and bullied into offering his resignation, which the president then declined to accept.

Senators obviously have a lot to cover, and Sessions showed in his June appearance before the Senate Select Intelligence Committee that he will try to avoid answering some of the most pressing questions. Here are ten important ones on which Senators should press him.

1. Were you aware when you signed off on FBI Director Jim Comey’s firing that the president was unhappy with his handling of the Russia case?

Sessions refused to answer this question when it was posed by Senator Diane Feinstein during his intelligence committee appearance, claiming he needed to preserve the president’s right to assert executive privilege over confidential conversations. But President Trump has not asserted executive privilege over these conversations, and as Senate Democrats pointed out in a letter last week, Sessions has not formally asked Congress to hold its questions “in abeyance” while he does. There is longstanding precedent for litigating or negotiating executive privilege claims, but Sessions, like other administration officials, has sought to reap the benefits of executive privilege without the president actually asserting it, leaving Congress with no ability to challenge its validity.

The answer to this question goes to the heart of the Judiciary Committee’s oversight responsibilities, because it directly bears on the attorney general’s fitness to continue serving. The president has essentially admitted–in both an interview with NBC’s Lester Holt and in Oval Office conversations with Russian officials–that he sacked Comey because of his handling of the Russia investigation. If Sessions knew that fact when he endorsed Comey’s firing, then he failed at the most important job of every attorney general: protecting the Justice Department’s investigations from political interference. (He might also have violated his own recusal from the Russia matter, though that issue pales in comparison to the larger breach.)

2. The New York Times reported on September 1 that the president and his aides drafted a letter firing Comey that was subsequently given to DOJ. Did you see it?

According to the Times, the president’s letter–which former Sessions aide Stephen Miller reportedly drafted–made explicit references to the Russia investigation and to Comey’s supposed assurances to the president that he was not personally under investigation. The Times reported that after White House Counsel Don McGahn raised concerns about the letter, it was given to Rosenstein and he was asked to prepare his own recommendation for firing Comey. If Sessions saw this letter, and its contents are as the Times reported, it would seem to confirm that Sessions did in fact know why the president was firing Comey.

3. Have you been interviewed by Robert Mueller’s team or informed by them that you are a subject of their investigation?

Sessions has potential exposure to the Mueller investigation in three areas: as a witness to the president committing obstruction of justice, as a co-conspirator to obstruction of justice, and as a possible subject for allegedly testifying falsely to Congress and failing to disclose meetings with Russian officials on his security clearance application. Rosenstein has declined to answer conversations about his interactions with Mueller by citing the department’s longstanding prohibition on discussing ongoing investigations. But Sessions is recused from this investigation, so his only relationship to it would be as a witness or subject, not as a Justice Department official overseeing it. The dodge that Rosenstein uses to avoid answering these questions does not apply to Sessions. The American people deserve to know whether the attorney general is himself under scrutiny by the special counsel.

4. Will you resign if the president attempts to fire Mueller?

The president has made no secret of his unhappiness with Mueller’s appointment, publicly mulling whether to fire him and berating Sessions for the recusal that Trump believes led to the special counsel’s appointment. After several weeks of White House leaks that Trump was considering firing Mueller, the president said in August that he had no such plans, though he has also said he would consider any investigation into his finances to be a red line. The methods by which the president could fire Mueller are complicated, but the simplest would be for Sessions to rescind his recusal and do it himself. The attorney general should make clear he will not participate in any attempt to fire Mueller and would resign if the president tried to otherwise circumvent or withdraw the Justice Department regulations governing Mueller’s appointment.

5. On July 21, the Washington Post reported that, according to U.S. intercepts, the Russian ambassador to the United States told his superiors that you discussed “campaign-related matters, including policy issues important to Moscow” when you met him in 2016. Is this true?

Sessions’ accounts of his meetings with Russian officials have evolved dramatically. First, he said such meetings never took place. Next, he admitted they met, but denied discussing any campaign business. By the time he testified before the intelligence committee, he only denied discussing any interference in the election, and claimed he could no longer recall any further details. Sessions’ spokesperson declined to comment on Kislyak’s reports to superiors; this would be a good opportunity for him to clear the air.

6. On July 24, President Trump tweeted that you should be investigating “Crooked Hillarys [sic] crimes & Russia relations.” Has he ever asked you to begin, alter, or end a criminal investigation into anyone?

Except for relatively narrow exceptions that mostly involve national security cases (usually terrorism or espionage), under longstanding norms the Justice Department does not discuss criminal investigations with the White House. This norm–meant to insulate the department from political interference–is a bedrock principle on which the sanctity of the federal criminal justice system rests, and Trump has repeatedly shown his disregard for it. Trump has put Sessions under enormous pressure through his public and private attacks, and the Senate should look for an assurance that Sessions has not allowed the White House to corrupt the criminal investigative process.

7. On July 5, the New York Times reported that White House advisers have discussed using the Time Warner-AT&T merger, which Justice’s antitrust division is reviewing, as leverage over CNN’s coverage of the president. Has anyone at the White House raised such an idea with anyone at the Justice Department?

As with criminal investigations, antitrust enforcement matters are typically not discussed between the White House and Justice. In fact, President Richard Nixon’s meddling in the antitrust division’s review of a merger between ITT and the Hartford Fire Insurance Company ultimately figured into the House Watergate Committee’s investigation.

8. On July 27, Anthony Scaramucci, then the White House communications director, said he contacted you about investigating leaks. As you know, that would be a violation of longstanding Justice Department guidelines about contact between White House officials and your department. Did this conversation happen and have any other such contacts regarding criminal matters occurred?

Under existing Justice Department policy, only the president, the vice president, the White House counsel, and the deputy White House counsel may contact the attorney general about criminal cases. For national security matters, that circle expands to include National Security Council and Homeland Security Council staff. If Scaramucci was telling the truth, Sessions should explain how he handled this inappropriate request.

9. Do you believe the civilian justice system is an effective tool for prosecuting terrorists and holding them accountable for their actions?

Sessions has repeatedly made clear he believes military commissions are a better tool for prosecuting terrorists than Article III courts, despite the latter’s longstanding track record. Last month, Acting Assistant Attorney General for the National Security Division Dana Boente declined to answer whether civilian prosecution of terrorists is effective at all–a puzzling position for the head of the division largely responsible for such prosecutions. The Justice Department is currently prosecuting Ahmed Abu Khattalah, the ringleader of the 2012 Benghazi attack, in federal district court in Washington, D.C. It is not too much to ask that the attorney general express faith in his prosecutors’ abilities and the effectiveness of the federal judiciary.

10. According to Axios, you have told associates that every National Security Council staffer should be forced to submit to a lie-detector test in an attempt to find leakers. Would you be willing to take one about your meetings with Russian officials and your testimony to Congress about those meetings?

Admittedly, this one is a bit of a cheap shot. But given the glass house from which Sessions threw this stone at the mostly career public servants who staff the NSC–public servants who have already been subjected to enormous turmoil and abuse by this administration–the attorney general has earned it.