WASHINGTON — Republican Sen. Rand Paul surprised even Republicans on Tuesday by calling for Congress to subpoena the Trump whistleblower over unsupported allegations that the individual was involved in corrupt Ukrainian business dealings.

The president’s most ardent supporters in Congress have long insisted the real corruption in Ukraine was done by former vice president Joe Biden and his family rather than by President Donald Trump. Many have also called for outing the anonymous intelligence official who filed a whistleblower complaint alleging Trump demanded a political quid pro quo from the Ukrainian government — an investigation into the Biden family in exchange for hundreds of millions of dollars in military aid. But, until now, they had not brought those two lines of attack together.

Paul did not present evidence that the whistleblower was involved in shady overseas dealings, and his theory builds on a report from a conservative media site that identifies someone they believe could be the whistleblower. BuzzFeed News is not publishing that name and does not know the identity of the whistleblower. The New York Times reported that the whistleblower is a CIA officer previously detailed to the White House with expertise on Ukraine.

Paul said in an interview Tuesday that the whistleblower “is a material witness to the possible corruption of Hunter Biden and Joe Biden.” He said Congress should investigate the whistleblower’s ties to the Biden family and Burisma Holdings, the Cyprus-registered gas company that paid Hunter Biden $50,000 per month when he was on its board of directors.

“[The whistleblower] might have traveled with Joe Biden to Ukraine for all we know. We should look at his writings. We should know all of this stuff to see whether or not he has any intersection with Burisma and with Hunter Biden,” said Paul.

Asked if he had evidence for any of these suppositions, Paul said, “We don’t know unless we ask.”

There is no known evidence that the whistleblower was in any way involved in Hunter Biden’s business dealings. Even other Republicans seemed taken aback by Paul’s comments.

“What basis does he have to say that?” asked Lindsey Graham, the Senate Judiciary Committee chair. “He needs to tell us. You can’t ask a judge. You can’t ask members [of Congress], 'Do you want to subpoena this guy?' He might be this, he might be that.”

A lawyer for the whistleblower said Paul and others are using disinformation to victimize the whistleblower and distract from the substance of the allegations.

“I imagine at some point soon our client will be accused of masterminding JFK's assassination as well,” said Mark Zaid. “Any Member of Congress who pushes to expose the whistleblower will not only undermine the integrity of the system but will be disgracing their office and betraying the interests of the Constitution and the American people."

The Biden corruption narrative has it that then–vice president Joe Biden threatened to withhold $1 billion in aid unless the Ukrainian government fired a prosecutor general in order to stop him from investigating Burisma Holdings, the company for which his son worked. The story has been debunked. Contemporaneous and subsequent media reports found that the investigation into Burisma had already gone dormant, and the United States and European Union had pushed to remove the prosecutor general because he was widely seen as corrupt himself.

Though both are steadfast supporters of the president's, Graham and Paul have found themselves at odds in the impeachment saga. During a rally with Trump in Kentucky on Monday night, Paul called for Republicans to subpoena Joe and Hunter Biden as well as the whistleblower and for the media to print the whistleblower’s name. But Graham shot down the subpoena request and said his committee would do no such thing. He said Hunter Biden’s Ukrainian business dealings were outside of his committee’s jurisdiction.

He also pushed back against calls from Trump defenders to subpoena Rep. Adam Schiff, the Democrat leading the House impeachment inquiry. “I think you’ll destroy the two branches if we start calling each other as witnesses,” said Graham.

One area where Graham and Paul do agree is that the whistleblower’s identity should be made public. Several House Republicans concur. But this is far from a consensus in the Republican Party.

“I think whistleblowers have the right to remain confidential and that their privacy ought to be respected,” said Sen. Mitt Romney.

Other senators who pushed back against naming the whistleblower on Tuesday included Roy Blunt and John Cornyn, both members of Senate Republican leadership, as well as Lisa Murkowski, Shelley Moore Capito, Rick Scott, and Thom Tillis.

“The whistleblower should have the protections of anonymity,” said Capito.

Kadia Goba contributed reporting to this story.