WASHINGTON — It looks to many like a textbook case of obstruction of justice.

President Donald Trump fired James Comey several weeks after the FBI director says the president asked him — during a private White House meeting — to shut down the investigation of Michael Flynn, the ousted national security adviser who was suspected of having secret dealings with the Russians.

“I hope you can let this go,” Trump allegedly said, according to a memo written by Comey and described to multiple media outlets.

Assuming Comey’s memos are accurate, “the basis for an obstruction of justice charge suddenly got a lot stronger,” said Jennifer Daskal, an American University law professor.

“We now have an allegation that the president cleared the room of both the vice president and attorney general before expressing his not-so-subtle ‘hope’ that the Flynn investigation be dropped, followed by the firing of Comey when the ‘hope’ was not met,” Daskal said.

The White House has denied that characterization of the meeting. And some prominent lawyers urge caution in jumping to conclusions, noting that obstruction of justice is not easy to prove.

Under the law, it is a crime to “corruptly” seek to “obstruct or impede” what the law refers to as the “due and proper administration of the law.”

Much depends on an assessment of the president’s motive, legal experts say. It’s also noteworthy that in this case the dispute probably will not play out in a courtroom but in a public arena and in Congress, which has the final power to prosecute the president.

Former prosecutors and legal academics say they foresee at least three lines of defense for the president.

First, they can argue he was simply trying to protect a loyal adviser and was therefore not acting out a corrupt motive.

“He could say he felt bad for Flynn. He didn’t have a corrupt intent and was not trying to curtail a criminal case. He was just saying (to Comey), ‘It would be great if you gave him a break,’?” said Peter Zeidenberg, a former federal prosecutor.

It will be important to focus on what was said, added David Rivkin, who served as White House lawyer under President George H.W. Bush. “The question is, did this amount to a specific directive? If Mr. Trump had issued a clear-cut order to stop the investigation, Comey would have resigned. That did not happen. Therefore, what he said was much more attenuated.”

Second, the president’s lawyers could argue there was no crime here. The FBI’s investigation was at a preliminary stage and had not yielded indictments. Some lawyers say obstruction of justice charges are limited to interference in an actual criminal case, not an early stage of an FBI probe.

Elizabeth Price Foley, a law professor at Florida International University, said obstruction of justice law refers to a “pending proceeding.” Courts have interpreted that to refer to prosecutions and agency hearings. This would not include an FBI probe that has not yet led to criminal charges, she said. “While there may be understandable angst surrounding the purported Trump-Comey exchange, there does not appear to be a fair legal argument that the exchange constituted an obstruction of justice,” she said.

And third, the president’s lawyers could argue the Constitution gives the president broad powers over investigations and prosecutions. Conservatives in recent decades have invoked the theory of the “unitary executive” which puts the ultimate power in the president’s hands.

Rivkin acknowledged that Trump’s alleged interference in the Flynn probe could raise other concerns, since the investigation could turn up evidence that implicates him or his campaign aides. He and others agreed the public and political debate will turn on the president’s motives.

Zeidenberg, the former federal prosecutor, said Trump has helped build a case against himself.

“Most presidents in this kind of situation say: ‘We want to get to the bottom of this.’ They feign transparency because it looks good. He did the opposite. He put out statements and tweets saying this was a hoax and should be shut down,” he said. That furthers the impression the president has something to hide, he said.

Prosecutors in a normal case would also focus on the report from Comey’s memo that Trump asked the attorney general and vice president to leave the room.

“That seems highly suspicious. If it were an innocent request, why do you want the witnesses to leave the room?” he said.

david.savage@latimes.com