Nearly a month after being fired by President Trump, former FBI Director James Comey is set to appear Thursday before the Senate Intelligence Committee and testify that the president asked for his loyalty and to break off the agency’s probe into his national security adviser.

The answers that Comey gives to the questions he’s asked by members of the committee, including Sens. Susan Collins and Angus King of Maine, could affect the future of Trump’s presidency, especially if Comey’s testimony suggests the president attempted to obstruct justice.

Comey’s description of a series of encounters in which the president first demanded his loyalty, then later asked him to drop the portion of the probe dealing with former national security adviser Michael Flynn’s contacts with the Russians was revealed in a seven-page opening statement from Comey that the committee made public Wednesday.

In late March and early April, the president called Comey to ask what he could do to “lift the cloud” hanging over him, the statement says.

“I have been very loyal to you, very loyal,” Comey recalls Trump telling him at the end of their final conversation. “We had that thing you know.” Comey said he did not reply or ask “what he meant by ‘that thing.’ ”

The details of Comey’s statement are sure to kindle sharp questioning by members of the committee, and the Portland Press Herald asked several legal experts this week what they think are the most important things to look for when Comey testifies today. All of them emphasized information that might suggest obstruction, although several noted how difficult it is to convict someone for that offense, let alone a president.

Jay McCloskey, former U.S. attorney for the District of Maine

Here’s what experts say to watch for:

JAY MCCLOSKEY, former U.S. attorney for the District of Maine, now in private practice in Portland:

“The question that’s been bandied about is whether there has been any obstruction of justice by the actions of President Trump. Obstruction of justice is a very difficult crime to prove. You have to show that there was an intent to obstruct, and that Trump had the consciousness of wrongdoing when he was doing what he was doing. Ultimately, you have to find out what happened.

“As an investigator, you look for the facts. How did the meeting occur, what did Trump ask, how did Comey respond? Did he ask for loyalty? Did he ask you to drop the Flynn case? Were there any other efforts to put off the investigation? Was anyone else present? Who else did Comey tell?

“The question comes down to if there’s enough evidence that makes Trump’s actions questionable. Then it becomes a political issue as to what Congress wants to do with that.”

DMITRY BAM, associate professor, University of Maine School of Law:

“The big charge would be obstruction of justice, so if there was an order or instruction to stop investigating or to cancel something, that would probably be the biggest story. As a criminal charge, that’s not so easy to prove, but for purposes of impeachment, that’s really the court of public opinion, and that’s different. Impeachment is for ‘high crimes and misdemeanors,’ but what that means is ultimately up to what Congress decides satisfies that definition because there’s no official definition. It’s not like there would be judicial review – ‘did the Senate properly find there was a high crime or misdemeanor’ – it’s a political question.

William Yeomans, American University law school

“One important thing for me is: Is there anything that contradicts what the president has said, because one good way for presidents to get into trouble is to lie to the American people.”

WILLIAM YOEMANS, American University Washington College of Law, former U.S. deputy assistant attorney general, former general counsel to the Senate Judiciary Committee:

“The president has already confessed to obstruction of justice by stating he fired Comey to impede the Russia investigation. Bizarrely, Trump’s lack of credibility seems to work for him in this matter. People simply refuse to accept his confession. It will be up to Comey to confirm that Trump asked for Comey’s loyalty and encouraged him to drop the Flynn investigation before firing him. Maybe then people will be willing to accept Trump’s confession.”

SARAH KENDZIOR, scholar of authoritarianism, columnist at the Toronto Globe and Mail:

“There are two aspects to this: the crime and the cover-up, and Comey will be able to talk most openly about the cover-up and his own firing, as opposed to the other aspects of the investigation that is ongoing, in regards to what Russia actually did.

“I’m hoping he touches on what he knew last summer, because back then there were some fairly prominent people like (Senate Minority Leader) Harry Reid pressuring Comey to speak more openly about it.

“The more transparent and thorough he is, the more effective it will be in getting to the heart of what happened and to getting justice, but also conveying to the public the depths of this very complicated situation. It’s understandable that a lot of Americans are having a lot of trouble following all this. It’s a very dark moment in American history.”

Colin Woodard can be contacted at [email protected]