The president’s Twitter habits are getting him into even more legal murkiness.

A group of First Amendment lawyers sent President Donald Trump a letter on Tuesday asking him to unblock Twitter users whom he gave the digital cold shower after they chastised or disagreed with him on social media — citing that Trump’s Twitter space is a "public forum" so the ban is unconstitutional.

The Knight First Amendment Institute, a non-profit under the Knight Foundation and Columbia University, represents several Twitter users who have been blocked from accessing @realDonaldTrump after they wrote unflattering statements about the president.

The letter to Trump says his “Twitter account operates as a ‘designated public forum’ for First Amendment purposes, and accordingly the viewpoint-based blocking of our clients is unconstitutional.”

“We ask that you unblock them and any others who have been blocked for similar reasons.”

The White House did not immediately comment on the letter but the lawyers are prepared to go to court if the president does not heed their advice, said Alex Abdo, one of the lawyers representing the blocked users.

One user, Joseph M. Papp, was shut out of Trump’s Twitter feed on Sunday, after writing “Greetings from Pittsburgh, Sir” and “Why didn’t you attend your #PittsburghNotParis rally in DC, Sir? #fakeleader,” according to the letter.

The lawyers’ correspondence comes amid the administration confirming on Tuesday that the President’s tweets should be taken as official statements, which bolsters the lawyer's argument say legal experts.

“The president is president of the United States," said White House Press Secretary Sean Spicer, "so they are considered official statements by the president of the United States."

Trump tweets NurPhoto / NurPhoto via Getty Images

The legal argument, standing at the intersection of technology and the Constitution, is certainly novel but also unclear, so here’s are a few takeaways breaking it down:

What is the basis of this argument?

The Knight First Amendment Institute is arguing the "public forum doctrine" under the First Amendment, a longstanding, very traditional legal principle.

The doctrine essentially says that the government cannot engage in content-based or viewpoint-based suppression of speech in areas of where public discourse takes place, said Neil Richards, a professor at the Washington University School of Law.

Lawyers for the blocked users argue that because Twitter has become a "forum for expression in which you [Trump] share information and opinions relating to government policy with the public at large, and in which members of the public can engage you, engage one another, and sometimes elicit responses from you" it becomes a public space.

"The interesting thing about this argument is that a private host, Twitter, is being likened to a public space," said Morgan Weiland, an attorney and scholar at Stanford University Law School’s Center for Internet and Society.

But the argument enumerated by the lawyers notes that “even if the space in question is 'metaphysical' rather than physical; even if the space is privately rather than publicly owned” the doctrine still applies especially since Trump has turned Twitter into the “official bull horn” Abdo said.

Twitter has now become a place where debate and conversation with government officials, especially Trump who uses Twitter for public announcements, policies, and plans, so the first amendment should apply in these places as well, Abdo said.

The White House announcing Tuesday that Trump's tweets are "official statements" also helps the argument, he said.

The issue is that courts have traditionally struggled even in physical spaces to identify what is a public forum so this is really becoming a cutting edge argument, Richards said. "and the outcome will be very unclear," he said.

The letter says that users who don’t have access to Trump’s account are deprived of their freedom of speech since they “limited in their ability to participate in comment threads” associated with the President’s tweets.

The blocked users also cannot follow the president on Twitter, are “limited in their ability to view, find, search tweets" based on things he's said, the letter said.

Abdo and the rest of the lawyers argue that the users blocked by Trump expressed viewpoints that the president found critical or mocking — which is content-based discrimination, he said.

The key issue is ensuring citizens are not kept out because of their viewpoints or what they have to he said. “Under the argument, they should not be excluded from a public forum and if they are that is suppression of speech,” he said.

The two large injuries here are the first, that the blocked users don’t get to tweet at the president and second, that they don’t get to hit reply all to the Twitter discussion, Richards said.

“But just because you are protesting doesn’t mean a government official has to listen,” he said. Again the law allows you to protest but because this area is so new, it's hard to say if blocking a Twitter user is paramount to suppressing their speech, he said.

The public forum doctrine only applies to government, so private users don’t need to worry about potential violations, said Weiland. If applied to the president however, a court ruling could trickle down to Congress and local politicians.

There are very different set of standards for public and private individuals so even if this goes to court and the court agrees with the Knight Foundation, this would only be about government officials, she said.

Although it is in interesting point that the President uses his personal Twitter as opposed to the official POTUS account, she said.

The Knight Institute says the private-public line was totally blurred with the president unabashedly mixed the two when he tweeted "official statements" from his private account.

“Certainly not every government official uses social media accounts as official places of public policy but because the president uses Twitter to describe his decisions and policies that is what converts Twitter into a public space that is not personal or private,” Abdo said.

What about hateful or obscene tweets at the president?

Just like any public forum, there are "time, place, and manner limits" to what is allowed under the doctrine, Richards said.

For example, you generally can't hold a protest rally in the middle of the night, or block rush hour traffic, he said.

“Arguably, and very arguably hurling expletives at the President could fall under manner restriction, but the Supreme Court has said that one man’s profanity is another man’s lyric,” he said. “Perhaps there may be some additional power in a public forum to make this nice but that’s really murky,” he said.

But the first amendment doesn’t let you shut down obscene or hateful speech,” said Abdo.

If the president were to establish some rules of the road when it comes to content regulation, like limiting the number of tweets people can put on his page so everyone can get a chance to weigh in, then those are acceptable “rules of the road” he said.

"Provided that they are applied evenhandedly," he said.