(WASHINGTON) -- Senate Republicans have announced plans to launch their own probe into former President Joe Biden over his cognitive abilities while in office, claiming they want to investigate who was running the country during what they call Biden's decline.
Republican Sens. Eric Schmitt and John Cornyn will co-chair a first-of-its-kind Senate Judiciary Committee hearing next month on the subject, which they say was covered up by members of the media. The focus echoes President Donald Trump's oft-repeated claims about Biden's mental fitness while president and criticism of Biden's use of autopen, a mechanical device to automatically add a signature to a document that's been utilized by several past presidents, including Trump in his first term.
"We need to get past the failures of the media, which were legend as you pointed out, or the political issue of 'were you for Biden or against Biden?' This is about a constitutional crisis, where we basically have a mentally incompetent president who's not in charge," Cornyn said Thursday on Fox News' "The Will Cain Show."
"The question is: Who is in charge? Whose finger is on the nuclear button or has the nuclear codes? Who can declare war? How do we defend the nation when we have basically an absent president? And those are constitutional issues we need to address and correct," Cornyn said.
On Friday, after delivering his first public remarks since his office announced he had been diagnosed with prostate cancer, Biden responded to reporters who asked him about Democrats who say he shouldn't have run again. "Why didn't they run against me then? Because I'd have beaten them," Biden said, adding that he has no regrets.
Biden denied any accusations of mental decline, saying that he's proud of his record as president.
News of the upcoming hearing comes after Cornyn penned a letter to Attorney General Pam Bondi last week, urging the Justice Department to investigate whether the Biden administration was being lawful in how they presented his cognitive condition to the country.
He asked that the Justice Department open a probe into "any potential violations of federal law surrounding the representations made to the American people about the health and wellbeing" of Biden.
"Congress' responsibility is actually bigger than just that. It is to provide oversight and to make sure that there's more transparency for future presidents so we understand how this happened and how can we prevent it from happening again," Cornyn said on Fox News.
Cornyn, in his letter, cited the May 18 report from Biden's representatives that announced he had been diagnosed with late-stage aggressive prostate cancer.
Other Republicans have also been calling for answers about Biden's health during the course of his presidency.
White House press secretary Karoline Leavitt told reporters on Thursday that former first lady Jill Biden should testify in front of Congress over the alleged "cover-up" of Biden's health.
"I think, frankly, the former first lady should certainly speak up about what she saw in regards to her husband and when she saw it and what she knew," Leavitt said.
"I think anybody looking at the videos and photo evidence of Joe Biden with your own eyes and a little bit of common sense can see, this was a clear coverup, and Jill Biden was certainly complicit in that cover-up. There's documentation and video evidence of her clearly trying to shield her husband away from the cameras," she claimed.
House Oversight Committee Chair James Comer, a Republican, recently called for a number of high-ranking Biden White House staffers to do transcribed interviews surrounding the topic of Biden's alleged decline.
Comer, speaking to Fox News' Sean Hannity on Wednesday, also suggested he might subpoena both Joe and Jill Biden, as well as former White House chief of staff Ron Klain, during the House's investigation of the former president's health and examination of his use of an autopen to sign legislation and executive orders.
Comer also recently requested that Biden's White House physician, Kevin O'Connor, appear for a transcribed interview as part of the investigation.
The calls for the probes into Biden come after the release of "Original Sin" by CNN host Jake Tapper and Axios reporter Alex Thompson, which made claims about "the Bidens' capacity for denial and the lengths they would go to avoid transparency about health issues."
In response to the book's release, a Biden spokesman said "there is nothing in this book that shows Joe Biden failed to do his job, as the authors have alleged, nor did they prove their allegation that there was a cover up or conspiracy."
"Nowhere do they show that our national security was threatened or where the President wasn't otherwise engaged in the important matters of the Presidency," the spokesperson said in a statement to ABC News. "In fact, Joe Biden was an effective President who led our country with empathy and skill."
Top Democrats have largely avoided defending Biden as new details surrounding the former president's health and alleged cover-up have emerged in recent weeks.
House Minority Leader Hakeem Jeffries, when asked by CNN host Wolf Blitzer on Wednesday whether Democrats can be trusted as new details are emerging, circumvented commenting directly on the former president's condition.
"What I can say is that we're not looking back, we're gonna continue to look forward because at this moment, we've got real problems that need to be addressed on behalf of the American people, including the Republican effort to snatch away health care, to snatch away food assistance and hurt veterans," Jeffries said.
During a recent press conference, Jeffries also accused Republicans of "peddling conspiracy theories" intended to make the country look "backward at a time when they are actually taking health care away from the American people."
"No, as House Democrats, we are going to look forward," Jeffries added.
Senate Majority Leader Chuck Schumer has also dodged any questions about Biden's health, responding to CNN's Kasie Hunt earlier this month by saying, "Kasie, we're looking forward."
But other Democrats, such as Rep. Ro Khanna -- who defended Biden's mental and physical fitness during the 2024 campaign -- admitted he was wrong, but said there wasn't a cover-up of ahead of the election.
"I don't think it was a cover-up ... but I do think that the advisers and people close to Joe Biden owe an explanation … What I don't think the Democratic Party can do is just say, 'Let's talk about the future. Let's move past this,'" Khanna told ABC News' "This Week" co-anchor Jonathan Karl last Sunday.