The usually quite certain justices of the U.S. Supreme Court seemed to be uncertainly groping their way on Tuesday, as they sought to craft a new rule for dealing with the social media age.

At issue were cases that test the ability of public officials to block critics from their "personal" social medial pages, a practice that Donald Trump often engaged in when he was president.

The first of Tuesday's cases dealt with two local school board members in Poway, Calif. They blocked two persistently critical parents from their social media pages, and the parents sued, contending the school officials had used their government authority to violate their First Amendment right of free speech.

Representing the school board members, lawyer Hashim Mooppan told the justices that the social media pages were extensions of the board members' campaign pages and thus were purely personal because the state had no control over them.

That prompted Justice Samuel Alito to ask, "What if you showed a Facebook page to a thousand people and 999 of them would think that this is an official page? Under your test, that wouldn't matter?"

"That shouldn't matter," Mooppan replied.

The example of former President Trump

"So that means President Trump's Twitter account was also personal?" Justice Elena Kagan interjected, raising the issue of then Trump's practice of blocking critics on his Twitter account.

"I think that was a harder question," Mooppan replied, noting that a government staffer facilitated Trump's page for him.

That didn't satisfy Justice Kagan. "I don't think a citizen would be able to really understand the Trump presidency, if you will, without any access to all the things that the president said on that account" she said. "It was an important part of how he wielded his authority. And to cut a citizen off from that is to cut a citizen off from part of the way that government works."

Who can be excluded?

Justice Sonia Sotomayor pressed lawyer Mooppan further, asking if a school board member's social media page is deemed to be personal, could he "exclude Muslims, Jews, whoever he wanted to exclude... because that's a social account?"

Mooppan replied that these were not government social media pages. They were campaign pages. "My clients were elected officials who have to run for re-election. So what they were doing is what incumbent officials all over the country do as a regular matter. They talk to their constituents to show what a good job they've been doing and why they should be re-elected." And they do that on their personal social media pages.

Several justices asked about school board members devoting their pages to school business. Why doesn't that transform their pages into a place where the public's business is being done? Mooppan replied that school business could just as well have been discussed in the board members' backyards, or for that matter, at a campaign event that is open only to fellow Republican or fellow Democratic party members.

Justice Amy Coney Barrett followed up, observing, "I think it's very difficult when you have an official who can in some sense define his own authority." After all, she noted, "My law clerk could just start posting things and say this is the official business of the Barrett chambers, right?"

Lawyer Mooppan replied, somewhat inscrutably, that "It becomes harder the higher up you go in the chain because it's harder to identify a superior who can tell you what to do."

What is state action?

Arguing the contrary position, on behalf of the blocked school board critics, lawyer Pamela Karlan contended that the parents were being denied access to important information about the public school system that is only available on the board members' personal pages.

Justice Alito asked how blocking a critic from a social media page is different from a public official at the grocery store deflecting a critic by telling her to call his office.

Karlan replied that when a public official is "clearly off duty, that is ... pushing the shopping cart down the aisle, arguably, they're not doing their job." But, she added, "If they say they're doing their job, then, yes, I would say the starting point is they're state actors," meaning they are exercising the authority of the state and their page is not purely personal.

Justice Brett Kavanaugh asked Karlan if her position would be the same if the White House press secretary were to invite a select group of reporters to her house for dinner, leaving out other members of the press. "Is that state action?" he asked.

Karlan replied that there would be "no meritorious constitutional claim" the uninvited reporters would "have a right to come to your dinner ... as opposed to you don't allow people to show up at press briefings altogether."

She contended that a public official, talking about public business, can't kick constituents off of his or her social media page without violating the constituents' first amendment rights.

"That's what makes this case so hard," opined Justices Kagan. "There are First Amendment interests all over the place."