House Judiciary Chairman Jerry Nadler is poised to hold a committee vote Wednesday to allow staff members to question Attorney General Bill Barr during a Thursday hearing. Barr has said he will not attend the hearing if the House Judiciary sticks to this new proposed format.

Allowing staff members – in addition to lawmakers – to question Barr, if the committee votes to permit it, wouldn’t violate any rules but Republicans have argued the move is without precedent.

Nadler’s office has cited several instances where congressional staff were allowed to question witnesses.

Facts first: The narrow question of determining “precedent” depends on how you define it, but CNN could not locate an instance where a Cabinet official was interviewed by staff members during a public hearing before the House Judiciary Committee. However, there have been instances where staff attorneys were permitted to interview witnesses. And ultimately this argument may have only political importance.

Nadler’s office cited several instances to support the idea that allowing staff to question Barr would not go against precedent, including public and private hearings.

Some instances occurred during impeachment inquiries into Presidents Richard Nixon and Bill Clinton. But Barr’s testimony is not part of impeachment inquiries, so such examples fail to establish precedent.

Nadler’s office also pointed to the investigation into the FBI’s handling of the probe of Hillary Clinton’s emails. Many of the interviews were with former FBI officials as well as former Attorney General Loretta Lynch. That’s a bit different from an interview with a current official. Additionally, the interview with then-Deputy FBI Director Andrew McCabe was not a public hearing – Barr’s Thursday hearing would be public.

The congressman’s office also pointed to the testimonies of then-Attorney General Ed Meese and then-Secretary of State George Shultz during the joint House and Senate hearings on the Iran-Contra scandal in 1987. A committee aide at the time told The Washington Post that “(t)here was also agreement that ‘if members of the Cabinet were going to be confronted, it should be done by senators and congressmen, not the staff.’” This would include Shultz and Meese.

Staff members were permitted to question former White House aide Oliver North.

Also cited was a House Armed Services subcommittee’s questioning of then-CIA Director James Schlesinger on the alleged involvement of the CIA in Watergate. Again, this does not directly parallel the House Judiciary allowing staff attorneys to interview Barr. It’s unclear, too, if Schlesinger was questioned during a private or public hearing.

But the suggestion that this goes against precedent might be somewhat irrelevant.

“Everything is negotiable here,” Robert Raben, who was assistant attorney general under President Bill Clinton, told CNN. “To pretend that there’s sort of an objective set of rules that people are deviating from is an absolute smokescreen.”

CNN’s Jeremy Herb contributed to this report.