The only way Biden can address concerns about his mental fitness is to debate Trump

President Joe Biden, following his impassioned partisan State of the Union speech last week, said jokingly in side remarks to longtime Rep. Jerry Nadler (D-N.Y.), “I wish I was cognitively impaired.” 

I have to admit it was reassuring to see the president comfortable with himself and full of vigor, forcefulness and even humor, even if he didn’t always have all the facts straight; especially disturbing when it came to slain Georgia nursing student Laken Riley (calling her Lincoln), or her alleged murderer (whom he called an “illegal,” offending his base). 

But whether you agree with Biden’s policies or not, the real question remains: How cognitively fit is the president? Consider that he has not undergone any cognitive testing that we know of or disclosed an MRI of the brain despite suffering from chronic atrial fibrillation, a condition that predisposes to mini vascular events in the brain (mini-strokes or cognitive problems) and sleep apnea, which a new study demonstrates is associated with a 50 percent increase in cognitive problems.

The public’s perception of Biden’s feebleness and cognitive dysfunction is not going to truly lessen without a bold intervention. The only way for Biden to partly assuage the public’s doubts is to take Trump on directly; to debate him in public, at least once.  

Some in the media have questioned whether Biden might be taking a form of stimulant intermittently, but I refuse to engage in this kind of speculation. What I can say is that at his age, 81, he needs to show a sustained focus to win over voters who have questioned both his age and his fitness. 

How will he do in a head-to-head matchup with former President Trump if he agrees to a debate? How will the teleprompter president do against the shoot-from-the-hip former president? I was surprised at how well Biden did debating Trump four years ago, but Biden doesn’t appear to have the same level of cognitive ability that he had even back then when he was Trump’s current age. 

When I interviewed President Trump at the White House back in July 2020, he not only didn’t prepare in advance, but he also didn’t ask to see the questions that I intended to ask him. It is hard to compare that to President Biden, who appears almost entirely dependent on the teleprompter. 

Don’t get me wrong, the State of the Union speech still stands as a cognitive win for the president, if for no other reason than he presented himself cogently, coherently and through themes regarding the economy and the border, which matter a lot to Americans. But so does the high price of food, and our borders remain as porous as ever, which, since Trump’s restrictions have been lifted, have led to a huge influx of more than 8 million migrants. 

I can tell you that I am concerned just from a public health point of view. I believe the current measles outbreak among unvaccinated migrants in a Chicago homeless shelter is tied directly to the fact that migrants don’t have the same level of measles vaccination as most citizens do.  

It is almost mind-boggling to consider that we are talking about an 81-year-old president who, if he wins reelection, will be age 86 when his second term is complete. America is watching to see if this president can maintain the vigor he showed last week over time. Most are highly doubtful, as they should be.  

Cognitive function may wax and wane, and having a good night’s sleep, exercising regularly and following a diet high in vegetables and other anti-oxidants helps. The key term is cognitive reserve, which means how agile a person’s brain is in using a range of skills to solve problems and show advanced judgment in coping with challenges. 

How much cognitive reserve does our president really have? We need to know. The more cognitive reserve the better the brain’s executive function. And of course, no one needs this ability more than our chief executive. 

It goes without saying that all of this matters because behind closed doors the actual job of the president is more about capacity and decisionmaking ability than appearance or public perception. 

One test of this that we are all looking forward to is a debate with the outrageous and largely unpredictable candidate Donald Trump. Is President Biden up to it? We all hope to find out.

Marc Siegel MD is a professor of medicine and medical director of Doctor Radio at NYU Langone Health. He is a Fox News medical correspondent and author of the new book, “COVID; The Politics of Fear and the Power of Science.