Social media platforms are the town halls of the 21st century, argue many First Amendment scholars. (Nicolas Asfouri/AFP/Getty Images)

A legal case that began with a dispute between a member of the Loudoun County Board of Supervisors and a constituent may help to set the rules for how government officials — up to and including President Trump — interact with the public online. A federal appeals court in Richmond will hear the case this week, and, while the stakes of the conflict may seem small at first — one man was banned for a day from an official’s Facebook page — it has potentially enormous First Amendment implications.

The case could establish a precedent that it is unconstitutional for government officials to block comments on their official social media sites because of distaste for a poster’s opinion. If that view becomes settled law, it could end up reshaping how Trump and his aides run his Twitter feed. And, given the ubiquity of online political communication today, such a decision would reverberate across the country.

These implications are why we have filed a friend-of-the court brief on behalf of leading First Amendment scholars in the Loudoun County case being argued Wednesday, and it is why the Georgetown University Law Center institute where one of us works previously filed a brief in support of some of the people whom Trump has blocked on Twitter.

The case being heard this week has its origins in February 2016, when Phyllis Randall, chair of the Loudoun County Board of Supervisors, took away one of her constituent’s posting privileges on a Facebook page she had set up to discuss local issues; Brian Davison’s offense was to have accused the local school board of having conflicts of interest (specifically, self-dealing involving family members). She relented the next day and let Davison post. But he sued, and a trial court in Virginia declared the blocking of the constituent’s account violated the First Amendment.

The trial court’s ruling is consistent with long-standing Supreme Court precedent holding that, while government officials are under no obligation to create speech forums of any kind, once they do, “viewpoint-based discrimination” becomes unlawful. The classic public forum is a public park or street corner, but in a 1985 case called Cornelius v. NAACP Legal Defense and Educational Fund, Inc., the Supreme Court explained that its precedents demonstrate that the government can create many others: “In addition to traditional public forums, a public forum may be created by government designation of a place or channel of communication for use by the public at large for assembly and speech, for use by certain speakers, or for the discussion of certain subjects.”

By that standard, there is no question Randall created a forum for speech when, acting in her official capacity, she set up a Facebook page she said would enable her “to hear from ANY Loudoun citizen on ANY issues, request, criticism, compliment, or just your thoughts.” Having set up the forum, Randall was barred by the First Amendment from banning Davison’s speech simply because she disagreed with it.

One of Randall’s defenses is her Facebook page amounts to speech by a government official and courts have granted significant leeway for officials to control such speech. (Citizens have no right to have their views represented in an official’s news releases or speeches, for instance.) But Randall set up the page in such a way that it encouraged comments from her constituents, and no one could possibly confuse such citizen comments as conveying a message from the government.

Nor, contrary to Randall’s position, does the fact that Facebook is a private company — and blocking other users from a page you set up is one of many features it offers — change the constitutional analysis. Long-standing precedent makes clear government officials cannot avoid the First Amendment’s requirements simply by hosting public meetings on private property. After all, Randall, and not Facebook, is the one who banned Davison.

Randall also contends a brief ban of 12 hours was too insignificant to count as a First Amendment violation. As the trial court concluded, however, even a short ban punished Davison for his views and could have a chilling effect on other citizens’ speech.

The arguments in Davison v. Randall could serve as a preview of another case heading for a three-judge panel of appeals court judges in New York this winter. Last year, Twitter users blocked from the @realDonaldTrump account sued the president for unconstitutionally suppressing their voices. Earlier this year, a federal trial court in New York agreed that their First Amendment rights had been violated. The Justice Department has appealed the case.

We believe the district court in the president’s case also got it right. While, at first blush, the president’s Twitter account may seem less like a public forum than a Facebook page devoted to local issues, there are important similarities. First, although @realDonaldTrump is technically nonofficial — the purportedly official Twitter account is @POTUS — Trump still conducts official business on the account — including announcing his nominees for Cabinet positions and sharing the results of official diplomatic meetings.

He (or others who help run the account) also make use of certain features that turn it from a system of one-way proclamations into a forum: Trump engages regularly with those who “like” and retweet his own remarks. In turn, the threads created under his tweets by constituents using Twitter’s “Reply” function result in a robust exchange of views. Once Trump enabled certain features — such as by ensuring replies were visible to him — the First Amendment barred him from deciding which views he would be willing to tolerate.

As former national security lawyers in government, we are well aware of the challenging issues the intersection of the First Amendment and rapidly advancing technologies can raise. But applying long-standing constitutional principles to novel factual circumstances is something courts do every day. We think the case in Loudoun County implicates the most basic of the First Amendment’s mandates: Government officials cannot silence views simply because they dislike them.

Indeed, given how central social media have become to political dialogue in this country — as the Supreme Court itself recently recognized — it is especially important to ensure First Amendment protections govern in digital spaces.

It is true the government has an interest in not seeing official Twitter feeds and Facebook pages get overwhelmed by disruptive spam or obscene, threatening, abusive or harassing language — a disturbing possibility. But we think a federal-district court in Kentucky erred when it stated that applying the First Amendment to social media could prevent government officials from being able to stop their accounts from degenerating into online cesspools. (The court made that argument in siding with Kentucky Gov. Matt Bevin (R), who wanted to be able to continue blocking followers.)

The Supreme Court has long been clear the government can engage in what is called “content neutral” speech regulation, and such regulation can promote dialogue. Consistent with this interpretation, government officials are starting to develop policies that forbid spamming, violating copyright laws and harassment on official social media pages.

More work needs to be done to refine these policies, and we believe that both legal and technological expertise should be brought to bear on their development.

Even the best policies may still raise difficult First Amendment questions in their application to hard cases. But drawing difficult lines is hardly a challenge unique to the online world. Officials presiding over in-person gatherings also must enforce rules that forbid harassment, microphone-monopolizing harangues and other forms of speech that hurt the exchange of views.

Getting this right is important, as the stakes are high. Silencing voices criticizing the government on social media while permitting voices praising the government has become an all-too-familiar playbook for authoritarian regimes worldwide. Allowing government officials here in the United States to employ the same tactics would be a decidedly unhealthy direction for our democracy.

Our first line of defense is our judiciary, which can stop government officials from engaging in this slide through decisions that uphold the First Amendment. The second step must be to help government officials figure out how to facilitate genuine discourse on social media, so digital-age public forums prosper.

But that first step is a crucial one: getting courts, and the public, to see that today’s digital town halls deserve as much protection as traditional in-person gatherings. That is what the First Amendment demands.