Criticisms mount that Biden is a 'shadow' of himself after disastrous debate: 'Not the same man' from VP era

The White House has attempted to dismiss President Biden's gaffes, miscues and mental acuity concerns as little more than the product of "cheap fakes" and misinformation, but one of Biden's current political rivals – who previously served alongside him – says unequivocally that the Biden seen during a disastrous national debate is "not the same man" he once knew.

Rep. Ronny Jackson, R-Texas, served as physician to the president during both the Obama and Trump administrations and previously worked in the White House Medical Unit during the George W. Bush administration. It was during his time spent serving under former President Obama that he was able to most closely observe Biden, then the vice president.

"I was in the White House when Joe Biden was VP, and the man we’ve seen since announcing his candidacy is not the same man who was VP for 8 years," Jackson said.

Fox News Digital gathered various videos showing how Biden’s once-cogent speeches and energetic public appearances during his days as vice president have given way to a drastically different demeanor as president.

Thursday evening’s debate against Biden's likely general election foe, former President Trump, significantly elevated concerns about Biden’s age and mental acuity.

AFTER BIDEN'S DISASTROUS DEBATE, CAMPAIGN EMAILS SUPPORTERS ON HOW TO DEFEND HIM: 'BEDWETTING BRIGADE'

The debate had a cascading effect within the media and some members of the Democratic Party, too, as even traditional left-wing allies slammed the president's performance as disastrous – with some calling on the president to step aside before the election.

As legacy media outlets such as the New York Times and the Chicago Tribune call on Biden to map out an exit plan – with the Times