Memo to President Trump: You cannot fire federal judges or intimidate them with your tweets. They have lifetime appointments for a reason: so they can resist the pressures of politicians like you, bullies who think bluster and bravado will always get them what they want.

The president has now extended his “running war” with the news media to the federal judiciary. After District Judge James Robart blocked Trump’s temporary travel ban — aimed primarily at refugees and Muslims — the president assailed him as a “so-called judge” who had made a “ridiculous” ruling.

In a later tweet, he continued his assault: “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 might well be right on the legalities, but no matter how the case eventually turns out, his attack on the judge is one more disturbing sign that this president does not respect the rule of law or the separation of powers.

Here’s Charles Fried, solicitor general under Ronald Reagan, who told The New York Times: “There are no lines for him. There is no notion of, this is inappropriate, this is indecent, this is unpresidential.”

And Bartholomew J. Dalton, president of the American College of Trial Lawyers: “It is wrong for the chief executive of the executive branch to demean a member of the judiciary with such language. This undermines judicial independence, which is the backbone of our constitutional democracy.”

This is not a minor or momentary incident. For one thing, during the campaign Trump showed his deep-dyed disdain for judges who dare to cross him. Remember: He called Judge Gonzalo Curiel a “hater” and said Curiel’s Hispanic heritage biased the judge against him in a civil case.

More seriously, the conflicts with Curiel and Robart could foreshadow many battles ahead. Since congressional Democrats are largely powerless to stop Trump’s appointments and legislative proposals, the courts loom as an increasingly important check and balance against unbridled presidential power.

As Sen. Patrick Leahy, the ranking Democrat on the Judiciary Committee, put it, this president “seems intent on precipitating a constitutional crisis.”

The conflict with Robart reinforces another unsettling trend in Trump’s approach to the presidency: his determination to define facts in his own way. He told Bill O’Reilly that implementation of his executive order was “very smooth” and inconvenienced only 109 people.

But that is flat-out false. His own administration admitted that 60,000 potential travelers were affected, and the chaos and heartbreak he caused were clearly visible to anyone with a TV and a pulse.

The point of Trump’s ban, as he put it on Twitter, is “about keeping bad people (with bad intentions) out of country!” But that is not what the ban does. There is no evidence — none — that refugees and immigrants have been a threat to national security. The ban does not keep out terrorists. It keeps out people who have been terrified by turmoil in their home countries.

Ten national security experts from the Obama administration made this point in a legal brief supporting Robart’s ruling. One of them, former CIA Director Michael V. Hayden, told The Washington Post that Trump’s order “didn’t solve a real problem and actually made the overall situation worse.”

Here are just a few of the “bad people with bad intentions” who were blocked by Trump’s order and freed by Judge Robart’s ruling:

• Tarek and Ammar Aziz are brothers from Yemen who joined their father after 15 years of separation. “Everything I didn’t do for them while I was here, I want to do,” said the elder Aziz. “I want to give them the things a father should. I want to give them love.”

• Zahro Warsame told the Post she borrowed $2,625 to buy tickets for her three daughters, whom she had left behind in Ethiopia. “It’s a miracle,” one of the daughters said after getting off the plane, “because I never thought I’d see my mother again.”

• Bahati Sudjonga, a 19-year-old Congolese man, grew up in refugee camp in Uganda after his parents were killed during a civil war. His two siblings settled in Boise, Idaho, last September, and when he was reunited with them this week, more than 100 people greeted him at the airport, reported the Wall Street Journal. Mayor Dave Bieter handed him a framed copy of a city council resolution declaring Boise a “welcoming city.”

Boise understands the spirit of America. The president does not.

Steve and Cokie Roberts can be contacted at stevecokie@gmail.com.