Sen. Lindsey Graham (R-SC) told Fox News’ Sean Hannity on Wednesday evening that he will call Rep. Adam Schiff (D-CA) to testify in the Senate if the House impeaches President Donald Trump.

Graham added that he would not allow a trial of President Donald Trump in the Senate based on hearsay evidence alone, and without testimony from the “whistleblower.”

Graham was speaking after the close of the first day of public hearings in the House Intelligence Committee as part of the “impeachment inquiry” authorized by Democrats in a House resolution that passed on party lines October 31.

After the first two witnesses testified, Democrats on the committee voted along party lines to table a motion made by Republicans to call the “whistleblower” — who admitted having no first-hand knowledge — to testify in person.

Republicans — notably Rep. Mike Turner (R-OH) — pointed out that neither of the two witnesses would qualify to testify in court, since they only had “hearsay” evidence, i.e. they did not see or hear anything relevant themselves.

The Sixth Amendment, which guarantees the right to confront one’s accuser, excludes hearsay evidence in most circumstances — especially when the direct evidence, in this case the transcript of the telephone call between the president and President Volodymyr Zelensky of Ukraine.

Graham, as chair of the Senate Judiciary Committee, and a former impeachment manager during the trial of former President Bill Clinton, would have considerable sway over the procedural rules the Senate would adopt for Trump’s trial if the House impeaches the president.

He declared that he would bar any case against the president based on hearsay alone, suggesting the prospects of a motion to dismiss. “Any resolution setting up a trial in the Senate — I’m going to make sure that hearsay cannot be the basis of an impeachment investigation,” he said.

“If you excluded hearsay, like every other court in the land, there’s nothing there,” he added. “If you invoked the hearsay rule, what would be left?” He described impeachment based on hearsay as “a threat to the presidency itself.”

Graham added that he would require that the “whistleblower” testify.

“Any trial in the Senate must expose the whistleblower so the president can confront his accuser. I will not accept a trial in the Senate until I know who the whistleblower is,” he said.

Graham also said that Congress needed to satisfy questions about the whistleblower’s potential motivations — and whether he had a role in former Vice President Joe Biden’s conflict of interest regarding his son Hunter’s board position in a corrupt Ukrainian company, Burisma. Biden threatened to block $1 billion of U.S. aid unless Ukraine fired a prosecutor who was, theoretically at least, overseeing an investigation of the company’s corruption.

Some media reports have suggested that the whistleblower worked for Biden under the Obama administration.

“Was the whistleblower connected to Joe Biden in any way? … Here’s the point: did the whistleblower engage in an effort to get the Ukrainian president [at the time, Petro] Poroshenko, to weigh in and stop the investigation of this gas company [Burisma]? Was there a connection between the whistleblower and Biden’s effort to call the Ukraine?

Graham also vowed that House Intelligence Committee chair Rep. Adam Schiff (D-CA) would be called to testify. Ordinarily, he said, he would not call a member of the House to testify, as a matter of mere oversight, but an impeachment trial was a special case.

“One of the witnesses will be Adam Schiff because if he, in fact, did meet with the whistleblower, and coached the guy up, I think that’s relevant to the impeachment inquiry itself,” Graham said.

Schiff denied having met the whistleblower, and denied knowing the whistleblower’s identity, in the hearing on Wednesday — but he was not under oath.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He earned an A.B. in Social Studies and Environmental Science and Public Policy from Harvard College, and a J.D. from Harvard Law School. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.