Rep. Trey Gowdy plans to grill former FBI Director James Comey about his decision-making as part of the House Oversight and Government Reform Committee's decision to re-examine the investigation into Hillary Clinton's private email server.

"Have to, won't we?" the South Carolina Republican told the Washington Examiner when asked about interviewing Comey.

Gowdy chairs the House Oversight and Government Reform Committee, which has opened a joint investigation with the Judiciary Committee in order to review the Justice Department's handling of the politically charged investigation. Gowdy is particularly concerned that "the decision to charge or not charge [Clinton] was made before all the witnesses were interviewed," but he emphasized that the investigation topics are structured in a nonpartisan way.

"Of the six things we listed with specificity, three of them are things Democrats gave a big damn about last fall," said Gowdy. "So, the question is, do they still? And three of them are things that Republicans cared about a lot last year, and the question is, do they still?"

The committees announced the investigation Tuesday morning, with an emphasis on Comey and why the FBI decided what information to reveal and when. Questions include whether the FBI made the right decision to say in public that Clinton's team was "extremely careless" in its handling of classified information, which Democratic critics protested was a breach of DOJ protocol. But the committee will also ask about the parallel refusal to confirm during the campaign that some of President Trump's campaign associates faced investigations over their apparent ties to Russia.

The investigators will demand an explanation for why Comey rocked the political world in October and November of 2016 with a pair of letters alerting Congress to a review of newly found Clinton emails. "Gather documents, gather access to witnesses, do your due diligence, and your investigation and see where it takes you," Gowdy said of the investigators' plans.

The practical significance of the investigation isn't clear. Gowdy, who chaired the select committee that investigated the Benghazi terrorist attacks and revealed Clinton's use of a private email server for classified government work, predicted that the probe wouldn't change the outcome of the Clinton email investigation. But he said it's a worthwhile effort to restore confidence in the Department of Justice.

"No, not at all, any more than James Comey can unsend a letter that he sent in October," he said when asked if anything might be reversed by the probe. "All of them are things that have caused people to lose confidence in the Department of Justice, on one side or the other, and there may be an eminently plausible explanation ... Comey may have a really good explanation for why he felt like he had to send a letter in October and there was no other means of notifying Congress, but we need to hear it."

Such transparency will require an extended private interview with the former FBI director, who was fired by President Trump in May, rather than a public hearing, to give lawmakers time to question him thoroughly. "I'm not a hearing guy," Gowdy said. "I'm a five hours guy, not a five minutes guy, so, not a hearing."