Also named as a plaintiff in the lawsuit is Daniel Scavino, the White House social media director.
U.S. District Judge Naomi Reice Buchwald in Manhattan stopped short in her written decision of ordering Trump or a subordinate to stop the practice of blocking critics from viewing his Twitter account, saying it was enough to point out that it was unconstitutional.
"We respectfully disagree with the court's decision and are considering our next steps", Kerri Kupec, Justice Department spokesperson said. While this sort of ruling does not demand that Trump do anything in response, Gu said that the group may file an injunction to compel him to unblock him or his co-plaintiffs if Trump does not do so voluntarily.
The Justice Department and Twitter are yet to comment on the ruling.
"No more is needed to violate the Constitution", she wrote.
"We hold that portions of the @realDonaldTrump account - the "interactive space" where Twitter users may directly engage with the content of the president's tweets - are properly analyzed under the "public forum" doctrines set forth by the Supreme Court", Buchwald ruled. According to Trump's previous claims, he is allowed to block users as he does the majority of his tweeting from his personal account, thus he is not restricted by the "public forum" designation.
The president's own personal rights can not be exercised "in a way that infringes the corresponding First Amendment rights of those who have criticized him", Buchwald said.More news: All Chilean bishops offer resignation to the pope over abuse scandal
As such, if he blocks people and thereby prevents them from seeing his messages, he is breaking the First Amendment.
Other media reports said the judge advised Mr Trump to mute critics if he doesn't want to see their activities, but they would be able to see and reply his own tweets.
McConnell said he was skeptical of the lawsuit when he first heard about it because Twitter is "really a 21st century way of writing, receiving letters".
As a result of the President's blocking of the Individual Plaintiffs from @realDonaldTrump, the Individual Plaintiffs can not view the President's tweets; directly reply to these tweets; or use the @realDonaldTrump webpage to view the comment threads associated with the President's tweets while they are logged in to their verified accounts. "N$3 o government official - including the President - is above the law", she wrote, "and all government officials are presumed to follow the law as has been declared".
When Gu was blocked, he said that he didn't feel pride like some Twitter users do when they are blocked.
The controversy stems from Trump's embrace of the platform as his soapbox to attack his critics, laud his supporters and announce administration policies.
Could this impact Twitter users in Australia? Scavino and Trump remain as defendants on the case.
The Knight Institute said it was lodging an appeal in the case of a Virginia resident blocked on Facebook by a local public official.