To the ramparts! The dread hand of fascism draws near.

Mainstream liberals have rediscovered Hannah Arendt. Orwell’s “1984” is streaking to the top of the sales charts. Every third magazine article is a dire warning about how we’re sliding into authoritarianism unawares. Celebrities are eagerly sharing wild-eyed Medium posts with titles such as “Trial Balloon for a Coup?” Suddenly, everything has echoes of the Third Reich.

Or does it?

Of course there is reason to worry about the Trump presidency, which in just 15 days managed to shock and alarm the reasonable of every constituency. But the fascination that some on the left have developed with authoritarian conspiracy theories as a reaction to our new administration is enough to make one cast them a skeptical eye. If anything, it sounds as though some almost want their worst political nightmares to come true. But why?

One reason could simply be a desire to place a confusing situation within an understandable narrative. Against expectation, an inexperienced, scandal-plagued former reality-television star won the 2016 election even though he lost the popular vote. The first days of Donald Trump’s presidency have been an unruly tumble of offensive executive orders, surprise firings, bungled press statements and near-universal expressions of disgust from experienced policymakers and political elites. For many liberals used to administrations that — whatever their flaws — tended to run on time and align with tradition, it is difficult to conceive of a president so unprepared and unaware.

So maybe, they tell themselves, he isn’t unprepared and unaware. Maybe it’s all part of a larger, nefarious plan. This would make sense of something otherwise alarmingly off-kilter. It may be a creeping evil, but at least it’s ordered.

And more than just creating a sense of structure, such whispers of trials to come impart a sense of meaning. Barack Obama’s 2008 campaign carried a heart-swelling, underdog message of hope and change, a cause that caught up and energized the young liberals who supported him. The following eight years had their ups and downs, but little matched that excitement — including Hillary Clinton’s lackluster run.

But now, a chance to join the fight against fascism? To identify with beleaguered populations threatened by a looming authoritarian regime? To become part of The Resistance? In an increasingly secularized and atomized age, we search for things that promise meaning and connection. At the extreme, individuals are drawn to radical movements such as the Islamic State. On a lesser scale, it could mean as much (or as little, depending on how real the threat is) as becoming a latter-day Weatherman.

Less philosophical, but no less important, could be the fact that it’s all rather . . . fun. Many on the left were quick to deride this sort of email-chain and blog-based theorizing when it appeared on the right after 2008, but its seductive pleasures are now a bit easier to understand. One can’t deny the thrill of sharing a solemn Facebook post and immediately being thanked for one’s insight. It is also true that much of this mental doomsday prepping is taking place on social media, where hysteria has always flourished. “To follow a minute-by-minute cycle of news is to be constantly threatened by illusion,” posited academic Alan Jacobs last month. When it comes to the Trump administration, the more frightening, it seems, the better.

But what if the fears are valid? If authoritarianism really is a threat, it will take more than sharing articles online to create a real resistance. That “fascist” immigration ban? One recent poll found that 48 percent of Americans support it. Engaging with those whose views on the Trump administration differ will have more of an effect on the future of the republic than whipping up frenzies in our online bubbles. Similarly, doomsday speculation is less useful than the engagement in which many, to be fair, have already taken part — protesting, advocating locally, calling representatives, getting, as Rep. Dave Brat (R-Va.) despaired, in their “grill.” Constant outrage and simmering fear are more likely to wear people down than keep them alert.

Of course speculation is tempting. Worry can even be useful. But hysteria? Less so.