Senate Judiciary Committee Chairman Lindsey Graham (R-SC) insisted on Sunday that the impeachment inquiry would be “invalid” and “a complete joke” without testimony from the anonymous “whistleblower” who triggered the probe and from Hunter Biden, whose work in Ukraine is at the center of the investigation.

“If they don’t call the whistleblower [to testify] in the House, this thing is dead on arrival in the Senate,” Graham warned on Fox News’s Sunday Morning Features, adding:

I consider any impeachment in the House that doesn’t allow us to know who the whistleblower is to be invalid because, without the whistleblower complaint, we wouldn’t be talking about any of this. I also see the need for Hunter Biden to be called to adequately defend the president and if you don’t do those two things, it’s a complete joke. … It’s impossible to bring this case forward in my view fairly without us knowing who the whistleblower is and having a chance to cross-examine them about any biases they may have.

On Saturday, Republicans submitted a list to House Democrats of eight witnesses they would like to testify as part of the chamber’s impeachment probe. Former Vice President Joe Biden’s son Hunter and the unnamed “whistleblower” are on the list.

Rep. Devin Nunes (R-CA), the top Republican on the House Intelligence Committee who submitted the list via a November 9 letter to Democrats, argued, “Because President Trump should be afforded an opportunity to confront his accusers, the anonymous whistleblower should testify,” adding:

Burisma has a reputation in Ukraine for corruption. According to public reporting, Burisma recruited Mr. [Hunter] Biden to its board to improve its public image at a time when Mr. Biden’s father, [then] Vice President Joe Biden, was the Obama Administration’s point person for Ukraine policy. … Mr. [Hunter] Biden’s firsthand experiences with Burisma can assist the American public in understanding the nature and extent of Ukraine’s pervasive corruption, information that bears directly on President Trump’s longstanding, and deeply-held skepticism of the country.

In response to what he described as the GOP’s “sham” request for witnesses, Rep. Adam Schiff (D-CA), the head impeachment inquisitor, ruled out testimony by the “whistleblower” and Hunter Biden. Both the anonymous leaker and Hunter Biden are at the heart of the impeachment probe.

The “whistleblower’s” testimony would be “redundant and unnecessary,” Schiff proclaimed in arguing against the leaker testifying.

An August 12 “whistleblower” complaint about Trump’s July 25 phone call with Ukrainian President Volodymyr Zelensky spurred the House impeachment inquiry. The complaint accuses Trump of engaging in a quid pro quo during the conversation in which the U.S. president attempted to pressure Zelensky to investigate corruption allegations against the Bidens, in exchange for aid. The Bidens deny any wrongdoing, as do Trump and Zelensky.

Some impeachment probe witnesses have denied that a quid pro quo took place. Others have presumed that Trump did attempt to coerce Ukraine to investigate corruption allegations against the former U.S. vice president and his son.

A top U.S. State Department official George Kent testified on October 15 that he warned the Obama administration in 2015 that the Ukrainian company that had hired Hunter the previous year, Burisma, was corrupt. The Obama administration ignored Kent’s concerns, however, and allowed Hunter to continue working at Burisma from 2014 until this year.

Kent is expected to testify in public, while Hunter Biden is not.

Breitbart News has repeatedly noted that there are signs Democrats are engaged in a fishing expedition, trying to expand the impeachment inquiry beyond the initial cause for launching the probe — the alleged quid pro quo during the Trump-Zelensky July 25 call. Now, the Democrats are seemingly trying to impeach Trump over “extortion” and “bribery.”

Naming the “whistleblower” as a witness in the impeachment probe could grant the leaker additional protections under the obstruction statute 18 USC § 1513(e), which makes it a crime to retaliate against a witness.

Citing legal experts, various news outlets, including the New York Times, Reuters, CNN, and National Public Radio (NPR), have determined that the law only prohibits the office of the intelligence community inspector general from revealing the “whistleblower’s” identity.

The law does not bar Trump and GOP lawmakers from outing the “whistleblower” to the public.

Under the law, it is illegal to retaliate against a whistleblower or make his or her work environment hostile, but proving retaliation can be difficult, the news reports noted.

It is also illegal to out the “whistleblower” if he or she is a covert agent. House Democrats pursuing the impeachment probe are expected to hold their first public hearing Wednesday.