First Amendment advocates challenging President Donald Trump for blocking some critics from following him on Twitter say his tweets are "an instrument of governance."
The lawyers asked a judge in papers filed in Manhattan federal court late Friday to rule in their favor and stop the president and his media team from blocking followers whose comments he doesn't like.
They did so after government lawyers argued in papers three weeks ago that a court should conclude Trump can choose not to hear some voices in an online account he began when he was a private citizen.
"The president uses the account for his speech, not as a forum for the private speech of others," lawyers for the U.S. Department of Justice wrote.
Trump's eight-year-old @realdonaldtrump account has nearly 42 million followers.
The lawsuit was filed in July by the Knight First Amendment Institute at Columbia University and seven people rejected by Trump after criticizing the president.
Lawyers for the institute and individual plaintiffs cited several instances when courts have described Trump's tweets in their rulings and described how they influenced legal conclusions. They also noted that the National Archives and Records Administration has advised the White House that the tweets must be preserved as official records under the Presidential Records Act.
"Against this background, it is plain that the @realDonaldTrump account is being used as an instrument of governance, and accordingly that it is subject to the First Amendment," the lawyers wrote. "The crucial fact here is that, since the president's inauguration, the president and his staff have used the @realDonaldTrump account almost exclusively for official purposes. Contrary to defendants' suggestion, this is not a situation where the president has made an isolated official statement in an otherwise personal or private setting."
The filing noted that the individuals who are named as plaintiffs were all blocked from Trump's accounts after commenting about tweets regarding official business.
The lawyers also said that Justice Department lawyers defending Trump were wrong to say the president has a right to choose not to hear some critics.
"The First Amendment forecloses the government from excluding individuals from a designated public forum based on viewpoint," the lawyers wrote. "Defendants argue that the president is above the law. He is not."