Comey should shed more light on whether the president is the subject of an FBI investigation into Russian election meddling, Graham said.
But later on Friday, two senior administration officials told The New York Times that Trump likely will not try to hinder Comey from testifying.
Three close associates of three contenders for the job, all of whom have been interviewed by Trump, said the candidates were summoned to the White House for 10- to 20-minute conversations with Trump, Vice President Mike Pence and Attorney General Jeff Sessions. Because he testified before Congress on May 3 and said that the president has never tried to do that for political purposes.
The White House has left open the question of whether Trump would intercede in order to scuttle Comey's testimony. But she said Trump wanted to allow for a "swift and thorough examination of the facts" related to Comey's ouster and the multiple investigations into his campaign's possible ties to Russian Federation.
The case centered around special prosecutor Archibald Cox's demand that the White House hand over tapes of conversations between Nixon and his colleagues in the Oval Office with respect to the Watergate scandal. "You don't do that I think by invoking executive privilege on a conversation you had apparently with nobody else in the room". Franken said that Mueller would determine if a crime had taken place, specifically whether the president obstructed justice, an impeachable offense, when he dismissed Comey earlier this month.
For Thursday's hearing, Trump could invoke executive privilege by arguing that discussions with Comey pertained to national security and that he had an expectation of privacy in getting candid advice from top aides. It is far more likely that Mueller will want the notes of Comey's presidential conversations to remain confidential until a sitting grand jury gets a look at them. If Trump pressured Comey to drop the Flynn investigation, as Comey is expected to testify, then Trump may have engaged in obstruction of justice, according to some lawyers.
Courts have often struck down attempts by presidents to invoke executive privilege and judges like to focus on the reason a commander in chief would want to keep something secret.
But being anxious about potentially embarrassing testimony is not a sufficient basis to invoke executive privilege.
"Does Mr. Comey agree that that is what was said? He can't put somebody in jail for violating executive privilege, and he can't fire him, because he's already been fired".
SC senator Lindsey Graham suggested Friday that a planned hearing next week with former Federal Bureau of Investigation director James Comey could descend into a political "hit job" if the director focuses only on reported conversations between him and the president. First, Congress would have to issue a subpoena requiring Comey to testify.
The remarks were the latest in a series of denials from Moscow that have had little impact so far on a political crisis in the United States over potential links between Russian Federation and Trump's inner circle.