Comey has also stated that Trump asked him for promises of loyalty - questions about which will likely be asked of Wray today.
He also said he had no reason to doubt the assessment of intelligence agencies that Russian Federation had interfered in the USA election through hacking, a conclusion of which Trump has been dismissive. And he said he "sure as heck" would not offer a pledge of loyalty to the president.
So, the Federal Bureau of Investigation director should be non-partisan and a philosopher, but also a loose-cannon detective who isn't afraid to get his hands, uh, dirty as long as justice prevails?
He said: "My loyalty is to the Constitution and the rule of law".
"First, I would try to talk him out of it, and if that failed, I would resign", Wray said.
Lawmakers from both political parties said they plan to ask Wray about his independence from the White House, and whether President Donald Trump has asked him for loyalty.
Trump, his son Donald Trump Jr., and Russian President Vladimir Putin won't be far from the forefront during Wray's 9:30 a.m. Indeed, the deputy attorney general appointed special counsel Robert Mueller soon after.
Christopher Wray, now a private practice lawyer, worked under George W Bush's administration as assistant attorney general in the USA department of justice's criminal division between 2003 and 2005.
Feinstein says she wonders, "Will Mr. Wray and the FBI pursue investigations with independence and vigor, regardless of who may be implicated?"
He also addressed an investigation into Russian meddling in the USA presidential election. But Wray pledged to guard the independence of the ongoing inquiry into possible collusion between the Trump campaign and Russian Federation, and said any effort to tamper with the inquiry would be "inappropriate".
"The FBI has a 10-year term limit, and no restrictions on any president to fire any director", Grassley said.
In a series of statements on Twitter, Trump called Mueller's investigation a "WITCH HUNT" based on the "phony" premise of possible collusion between Russian Federation and a cadre of Trump campaign associates.
"Our highest priority was protecting America from the threat of terrorism and strengthening national security", Wray said in a 68-page questionnaire to the committee about his earlier work at the department.
Trump Jr.'s attorney has dismissed the revelations as "much ado about nothing" and Trump Jr. said in a statement Tuesday morning that he thought the information being offered was "Political Opposition Research".
He said he felt it was not appropriate for the criminal division to "weigh in on" or provide legal advice on any particular interrogation techniques, but rather to be investigating and prosecuting cases of criminal abuse.
Wray's supporters repeatedly refer to his temperament as one of his best attributes, calling him a razor-sharp but low-key manager who looks to defuse tense situations, not escalate them.
This story has been corrected to show that Sen.
Wray was one of 10 former DOJ officials who submitted a letter to the Senate in 2013 that supported Comey's nomination to lead the Federal Bureau of Investigation.