Joe Biden accepted his party’s nomination for president last night, but those who made it happen have some serious soul-searching to do. Specifically, they need to decide whether continuing to hide this man from the American people is the right thing to do. Because he’s a nominee in name only — a NINO — and he won’t be governing should the Democrats win this election.

Last night’s speech wasn’t a train wreck — far from it. Biden spoke for 25 minutes, and he did a fine job. He didn’t stumble through it, nor did he have any of those cringeworthy moments we’ve seen far too many of lately, so he easily exceeded the lowest of low expectations. But that’s all he did. And since when is that the hallmark of a sharp and able mind? Regardless of how well he read the words off the teleprompter, the Joe Biden we saw last night simply wasn’t the man he was two years ago, or five years ago, or five decades ago, when he first began talking about the U.S. Senate seat he won in 1972.

If you yourself are an older American, think about how much you’ve aged since the Berlin Wall went up, or since Roger Maris broke Babe Ruth’s single-season home run record. That was 1961, the year Biden graduated from high school. If you’re old enough to remember those events, you’re probably old enough to give thoughtful and honest consideration to a simple question: Are you as sharp now as you were then?

Ever had brain surgery to remove an aneurysm? Joe Biden has. Twice. Both of them back in 1988.

Last night, the Democrat nominee looked all of 77. There’s no shame in that, of course, nor anything disqualifying about it. Donald Trump is also in his 70s, and he doesn’t hit his tee shots like he used to. But the president still sounds good, still sounds engaged, still sounds like he wakes up every morning just itching to put CNN’s Jim Acosta in his place. When he leads one of his signature rallies, Trump typically riffs nonstop for 90 minutes — no notes, no net. Biden, on the other hand, is being hidden, protected, forbidden from mixing it up with the media. And what he did last night is no substitute for real rhetorical combat.

Think about it: When was the last time Biden sat down for a lengthy, no-holds-barred interview? And not with a partisan lickspittle like Chuck Todd or George Stephanopoulos, but a real journalist like Bret Baier or Chris Wallace.

Yesterday, John Harris put together an interesting piece about Joe Biden’s age. How old is he? “Well,” as Harris writes, “he is older than 94 percent of all living Americans, and older than 96 percent of all people alive on the planet, according to demographic data compiled by the United Nations.”

The point is, Joe Biden is old, and he’s repeatedly demonstrated a degree of cognitive impairment for anyone willing to watch. According to the Mayo Clinic, mild cognitive impairment, or MCI, is the term used to describe “the stage between the expected cognitive decline of normal aging and the more serious decline of dementia.” Its symptoms include a slipping of memory or mental function, a loss of one’s train of thought, a feeling of being overwhelmed, and impulsiveness, poor judgment, irritability, and aggression.

If Biden doesn’t have MCI or even dementia, how do we explain this video and all the others like it?

This morning, The Wall Street Journal editorial board asks, “What does [Biden’s] long political career tell us about how he’d govern?” But that’s the wrong question. The correct question is, Who will be governing should Joe Biden win the election?

Given the radical leftward lurch of the Democrat Party, the American people deserve an answer. And they need to know definitively that Joe Biden is a nominee in name only.

Don’t miss our other coverage of the DNC: Day One, Day Two, and Day Three.