Inauguration Day was a moment of intense relief for tens of millions of Americans. The country's highest office was no longer occupied by a malicious and mendacious reality-show star who devoted most of his days to antagonizing his opponents and hardly any time at all actually governing.

That in itself was something good and important.

As for the man who replaced him, Joe Biden might be a little past his prime, but he clearly wants to do better than his predecessor at responding to the range of problems confronting the country, foremost among them the pandemic that has killed more than 400,000 Americans and its economic fallout. To do so, Biden has assembled a team of highly competent and experienced policy analysts, managers, and bureaucrats who hope to make a positive difference.

These early efforts, combined with Biden's inaugural address promising unity and conciliation with Republicans, produced a groundswell of good feeling on Wednesday afternoon and on into the evening, as a massive fireworks display illuminated the Washington Mall, replacing the scenes of insurrection a mere two weeks earlier with a more stirring, inspiring, and inclusive tableau.

The mad king is gone! The adults are once again in charge! America is back!

I want to believe it. I want members of my family swept up in the thrill of it all to enjoy the feeling. But I'm not letting down my guard just yet.

Hope is a funny thing. It's hard to live without it. This is probably true for all human beings, but it may be especially so for Americans, for whom hope for a better future serves as fuel for just about everything we do, both individually and collectively. We're a nation of strivers, always moving forward with irrepressible nervous energy. But striving for what? For a brighter tomorrow — with more money, more prestige, more fulfillment, more and better medicines, more and better forms of entertainment. The list goes on.

The political left is thoroughly animated by hope for progress — more equality, more freedom, more justice for more groups of people, with each reform, each expansion of the bounds of inclusivity, shriveling into inadequacy the moment it is achieved, replaced with the next goal, and then the next, seemingly without end. Progressives see the world as badly broken but fixable. The fixing is the point — of politics, maybe even of life itself. And hope makes it possible.

The political right has its own version of hope as well — though instead of progress toward an ever-receding endpoint of perfect equality, freedom, and justice, conservatives (in their more reactionary modes) look backward toward an original state of perfection from which we've fallen away and to which they hope to return, through the recapturing of past glory and greatness. We go forward by going back, renewing ourselves by drinking deeply from the forgotten but perennially recoverable wisdom of our forefathers.

Capitalistic and scientific striving, exertions in favor of moral progress, the impulse toward cultural return — hope plays a decisive role in all of them. It is what enables combustion in the motor of our practical pursuits.

That makes it sound wholly good. But hope has a downside — and that is disappointment when it gets dashed. And disappointment can easily curdle into despair, especially when the move from hope to disappointment gets repeated and becomes a recurring cycle.

On an individual level, despair is next of kin to depression. It can eat away at lives and communities. When that despair gets translated into politics, it tends to get uglier, more nihilistic. There's a reason why those areas of the country most plagued by despair rallied around the funhouse populism of Donald Trump, which promised a cartoonish return to past greatness in a language and attitude thoroughly suffused with the basest vulgarity of the present cultural moment.

But wait — doesn't this get things backward? Isn't the problem of despair a function not of repeatedly dashed hopes but hopelessness? Shouldn't we consider the rejuvenation of hope the solution to, rather than a source of, our problems?

Maybe. But only if the hopes are achievable. Otherwise, further rounds of disappointment will be assured. "Aim low: succeed" — that should be our mantra.

Does the Biden administration grasp the need for moderation in this sense — not ideological moderation, but moderation in ambition? In some respects, yes. It should certainly be possible to improve on the Trump administration's efforts at vaccine distribution. And when it comes to addressing the economic dimension of the public health crisis, I've been pleased to see the new president tempering ambition (the size of the proposed relief package) with simplicity (sending checks rather than designing technocratic Rube Goldberg contraptions to micromanage who gets the money and where it gets spent).

But achieving national unity? Ending our "uncivil war"? Eradicating systemic racism? Tackling climate change? On these and other issues, Biden appears to be raising hopes beyond what any president in our fractious, divided time could realistically be expected to achieve.

That has me anxious.

Barack Obama claimed to be animated by "the audacity of hope." He swept into office on a wave of high expectations, powered by talk of enacting bold (but underspecified) change. His two terms in office ended with a nearly successful electoral insurrection from the left within his own party, and a successful right-wing one in the opposing party. Now Trump's presidency has concluded with a crashing disappointment for those taken in by the conman-in-chief.

It's possible that this most recent shock will sober up the right, inspiring a long-overdue rendezvous with reality. But I wouldn't bet on it — any more than I'd expect to see the left placated by the kind of mostly symbolic gestures Biden will be able to achieve on social and cultural issues with Democratic margins in both houses of Congress so narrow.

Which means things remain precarious — certainly not as much as they were a little more than two weeks ago, when the president incited thousands of insurrectionists to storm the national legislature in a doomed bid to overturn a democratic election. But definitely more than one would suppose from following the giddy media commentary on the events of Inauguration Day.

By all means, know hope. But please, with moderation.