Uh-oh. Joe Biden is talking unity again.

It came last week at a CNN town hall in Milwaukee in response to a question about how he will bring Americans together. “I take issue with what everybody says about the division,” he replied. “The nation is not divided. You go out there and take a look and talk to people, you have fringes on both ends, but it’s not nearly as divided as we make it out to be.”

Regular readers will be familiar with my take on unity, last offered in January when Biden made a plea for it in his inaugural address. I consider it, at this stage, a pipe dream. As you would not ask a battered wife to seek unity with the husband who beat her, you cannot ask people of color to seek it with bigotry or Muslims with Islamophobia or LGBTQ Americans with homophobia or undocumented workers with xenophobia or fact-based Americans with utter hogwash. Yet bigotry, Islamophobia, homophobia, xenophobia and utter hogwash are, increasingly, the only things the political right has to offer.

So from where I sit, Biden speaks nonsense. But maybe that’s not the worst thing in the world.

I’m remembering another president who spoke nonsense. This was on March 4, 1933. Having just taken the oath of office, Franklin Roosevelt faced a nation mired in economic collapse — the unemployment rate near 25 percent, GDP down by 30 percent, one in five banks failing — and promised a revival. “The only thing we have to fear,” he asserted, “is fear itself.”

And yes, the words are stirring. But if you think about it, they are also patently ridiculous. Americans, after all, had plenty to fear: joblessness, homelessness, hunger, and the prospect of national collapse topping the list. Yet Roosevelt’s words rallied and inspired a dispirited nation. Almost 90 years later, they offer a useful challenge to skeptics like me, a reminder not to underestimate the power of presidential optimism. Or, indeed, the power of a president’s character.

When Bill Clinton was pilloried for sexually exploiting a naive young woman and then lying about it, it was common to hear his defenders opine that it didn’t matter what kind of man a president was, so long as he did the right thing politically. As Barbra Streisand famously snipped, “We elected a president, not a pope.”

If the last four years accomplished nothing else, they should have put permanently to rest the notion that presidential character is unimportant. The kind of person a president is has a lot to say about the kind of nation we will be. It is his or her job to make entreaty to the best in us, the highest and most noble in us, to speak into existence that which is unlikely — indeed, that which may even be, or at least seem to be, patently ridiculous. That’s how Lincoln won a civil war, Roosevelt overcame a great depression and Kennedy sent men to the moon.

The memory of all that imposes upon me a certain duality of mind when Biden insists, against all the evidence of our eyes, our hearts and our logic, on American unity. On the one hand, you recall the march through Charlottesville, the breaching of the Capitol, the spinelessness, the faithlessness, the litany of lies and alibis that continues right up to the present moment, and the idea of unity with those people — yes, they have become “those people” in my mind — seems delusional, far-fetched, a mirage of shadow and smoke. On the other hand, it feels undeniably … right to once again hear a president call us toward higher purpose.

So yes, a duality of mind. I do not believe unity is possible.

But I’m glad Joe Biden does.

Leonard Pitts Jr. is a columnist for the Miami Herald, 3511 NW 91st Ave., Miami, Fla., 33172. Contact him via e-mail at lpitts@miamiherald.com.