Appellate lawyers from across the country wrote the letter to Acting Solicitor General Noel Francisco and Acting Attorney General Dana Boente complaining about the attacks, including a Twitter tirade against a judge who temporarily blocked one of Trump's executive orders.
The letter says that it is acting on the behalf of judges, who the signatories say can't respond to Trump's attacks as they are prevented from speaking out publicly due to ethical constraints.
This letter, first reported by law blog Above the Law
, is signed by 145 attorneys who maintain federal practices or have served as federal law clerks.
The author of the letter, Laura W. Brill, an appellate attorney and former US Supreme Court law clerk, wrote:
"Lawyers across the political spectrum believe that the President's personal attacks on individual judges and on the judicial branch are improper and destructive.
"Because judges face ethical constraints in their ability to respond directly, the letter calls on the President to retract and end such personal attacks."
On Wednesday, Trump criticized legal arguments against his temporary travel ban and lambasted the federal judicial system that's weighing it as overtly political.
"If the U.S. does not win this case as it so obviously should, we can never have the security and safety to which we are entitled. Politics!"
Over the weekend, Trump notably attacked a Seattle-based judge, Judge James Robart, after he temporarily blocked Trump's executive order
banning travel to the US from seven Muslim-majority nations.
"The opinion of this so-called judge, which essentially takes law-enforcement away from our country, is ridiculous and will be overturned!" Trump tweeted on Saturday.
The Ninth Circuit Court of Appeals is currently hearing arguments
on whether Robart's temporary restraining order (TRO) should stand.
"The President's tweet is a personal attack on a sitting federal judge based on a substantive disagreement on a legal issue in a case in which the President himself is a party," the letter states.
"Personal attacks of this sort are not befitting our Nation's Chief Executive, especially in referring to a member of a co-equal branch of our government."
Saturday's tweet was followed two days later with another suggesting that Robart's decision would be to blame should a terror attack happen.
"Just cannot believe a judge would put our country in such peril. If something happens blame him and court system. People pouring in. Bad!"
Trump -- even as he blasted lawyers contesting his immigration executive order -- detailed for the first time Wednesday his own hesitations about the controversial plan
before it was signed.
Speaking to law enforcement officials in Washington, Trump said he argued before the order was finalized for giving travelers a month's notice before cutting off entry to the US, but was overruled by law enforcement officials, who he didn't name.
Supreme Court nominee: Comments 'disheartening'
The lawyers are not alone. On Wednesday Supreme Court nominee Neil Gorsuch told a US senator that Trump's tweets about the judiciary were "demoralizing" and "disheartening."
In a meeting with Connecticut Democratic Sen. Richard Blumenthal, Gorsuch, who's largely been silent since Trump nominated him last week, took exception to Trump calling a federal judge in Seattle a "so-called judge" after blocking the President's travel ban.
"He said very specifically that they were demoralizing and disheartening and he characterized them very specifically that way," Blumenthal said of Gorsuch.
"I said they were more than disheartening and I said to him that he has an obligation to make his views clear to the American people, so they understand how abhorrent or unacceptable President Trump's attacks on the judiciary are."