It would have to be an exceptional act of patriotism.

As the campaign took shape about a year ago, it seemed to many of us that Biden was the ideal candidate. He had served in the U.S. Senate for an incredible 36 years. He withstood unthinkable personal tragedies and inspired us all. For eight years he was President Barack Obama's right-hand man, helping to guide the nation out of financial crisis, crafting a landmark expansion of the health care system and elevating our standing around the world. Moreover, he's a decent man: the anti-Trump.

Yet we knew going in that if elected, Biden would be the nation's oldest president. At age 78 on Inauguration Day, he would be eight years older than the oldest to serve before him — none other than Trump. At the end of one term he'd be 82; after two terms, 86.

At a recent CNN town hall in New Hampshire, Biden was asked about picking a running mate. He replied that "because I'm older, just like with John McCain, I have to pick someone, if God forbid something happened tomorrow… that the person is ready on day one to be president of the United States." Sorry, Mr. Vice President, that's not comforting.

Some Biden supporters have been willing to cast aside concerns about age. After all, House Speaker Nancy Pelosi, at 79, runs circles around younger colleagues; Supreme Court Justice Ruth Bade Ginsburg, at 86, seems as sharp as ever. But the nation has only one president, and he or she is tasked with what is arguably the most demanding job in the world. Statistically, Biden and others his age face increased medical and cognitive risks, as Biden seemed to acknowledge at the CNN town hall.

On caucus night last week in Des Moines, Biden looked lost as he struggled through a speech, with wife Jill close at his side. She seemed to hang on every word, hoping that a gaffe wasn't coming.

The word "perseveration" came to mind as I heard Biden say the word "folks" 11 times in just over 3 minutes. (Webster: "continuation of something, such as repetition of a word, usually to an exceptional degree or beyond a desired point.") A big deal? No. Just another small reminder that Joe Biden isn't the man for this moment.

In that Iowa speech, Biden reminded us, "Four more years of Donald Trump will fundamentally alter the character of this nation." But, sadly, Trump may have already fundamentally altered Biden's chances.

Beginning with the cruel tag "Sleepy Joe," Trump's campaign against the man he perceived as his greatest threat continued into the impeachment hearings, as the name "Biden" — referring to both father and son, Hunter — was omnipresent, thanks to the efforts of Trump's henchmen. Although Democrats and journalists strained to make clear that there is no evidence whatsoever of illegal behavior by either Biden, the stain caused by the proceedings is indelible.

It's frightening to imagine how Trump and enablers like Sean Hannity would pound away with ounces of truth and tons of lies about the Biden family's Ukraine undertakings. Damage to Biden's presidential campaign is brutally unfair, yet undeniably true.

Still, why not let the voters decide? Because Biden is casting a shadow that extends beyond his own candidacy. Sens. Cory Booker of New Jersey and Kamala Harris of California, as well as former Housing Secretary Julian Castro, might still be in the race had Biden not been a presumptive favorite among black and brown voters. It becomes critically important to determine sooner rather than later who would get that support if Biden were not a factor.

Then there's the matter of clogging the center lane. Those of us who believe that the Bernie Sanders wing of the party is not the best bet in this election are concerned about finding the strongest alternative — a progressive with some level-headed flexibility. Former South Bend, Indiana Mayor Pete Buttigieg and Minnesota Sen. Amy Klobuchar made good showings in New Hampshire. They and former New York City Mayor Mike Bloomberg, are jockeying for centrist support. Biden, as long as he stays in, is in the way.

Biden backers I spoke with across Iowa lacked enthusiasm. Their support for the dignified former vice president was almost perfunctory, as if Biden was the safe, default candidate to topple Trump. This election demands more.

I hope Biden believers don't think I'm jumping to an unreasonable conclusion based on caucus results from two small states, places that aren't representative of America or the Democratic Party. It goes beyond that, just as it's about more than gaffes or "Joe being Joe."

Here's the deal (as Biden is fond of saying): If Joe is really to be Joe, he will again demonstrate his love of country and party by yielding to a younger candidate with a less encumbered prospect for beating Trump.

Folks, we owe Joe Biden a lot, and he owes us a better chance in November.

(c) Peter Funt. This column originally appeared in USA Today.