Americans are used to the hurly burly of political and legal debate. But presidents historically have been careful about criticizing individual judges or their motives.
However, President Donald Trump tweeted and railed against the judges who have ordered a temporary halt to his ban on people entering or returning to the U.S. from seven mostly Muslim countries.
The president's rhetoric left many lawyers and historians on both the right and left aghast, or at least scratching their heads.
Trump's fighting words
In the space of one week, President Trump has belittled all four judges who have ruled against him so far in the travel ban case. He referred to Judge James Robart, a George W. Bush appointee who temporarily suspended the travel ban, as a "so-called judge" whose decision was "ridiculous." In a three-part tweet, Trump added, "If something happens, blame him."
When the case was heard by an appeals court panel, Trump told a group of police chiefs that even a "bad high school student" could understand the ban was authorized by law.
"Courts seem to be so political and it would be so great for our justice system if they would be able to read a statement and do what's right," he said. "And that has to do with the security of our country."
The next night when the appeals court judges, including another Republican appointee, ruled unanimously against him, Trump responded combatively.
"It's a political decision and we're going to see them in court," Trump said.
Presidents, for the most part, avoid public feuds with courts for a practical political reason.
"Trump's statements are extremely self-defeating," observes Josh Blackman, a constitutional law professor at South Texas College of Law Houston.
"The more he says the courts are biased or will rule against him because they're stupid," comments Blackman, "it subconsciously increases the chances that they will rule against him."
The history of presidential restraint
There is a more serious reason Trump should avoid criticizing judges too, Blackman says. Under the U.S. system of three branches of government, the judicial branch — the courts — ultimately are the checks on the legislative and executive branches when they exceed or even abuse the limits of their power.
Understanding that, presidents going back to the founders have largely refrained from personal attacks on judges. President Thomas Jefferson, for instance, avoided publicly berating Chief Justice John Marshall about decisions limiting the power of the executive and the legislature.
"Jefferson spoke privately about what he called Marshall's 'twistifications' of the law, but he didn't do it publicly," says James Simon, the author of four books about the court and the presidency.
Jeff Shesol, author of a book about President Franklin Roosevelt's infamous court packing plan, makes a similar observation about the New Deal president. Roosevelt tried and failed to increase the number of Supreme Court justices so he could appoint more who agreed with him.
"Privately, Roosevelt was very bitter about his treatment at the hands of the Supreme Court," Shesol explains. "But even at the height of the court fight, he never allowed it to get personal in the way we have heard recently from Trump."
Modern presidents have followed a similar path. For instance, President George W. Bush was hardly pleased when the Supreme Court repudiated the system the Bush administration set in place for dealing with "enemy combatants" captured in Afghanistan and elsewhere.
After the Supreme Court ruled that prisoners at Guantanamo Bay had the right to challenge their detentions in court, Bush said tersely, "We'll abide by the Court's decision. That doesn't mean I have to agree with it."
President Barack Obama was widely criticized in 2010 for similar remarks about a campaign financing decision, mainly because he chose to comment at his State of the Union address, which the justices attend. Days later, Chief Justice John Roberts said the State of the Union had "degenerated into a political pep rally."
The tradition is that while presidents are free to criticize court decisions, they should avoid personal attacks on judges. Why? Because judges have no actual power. They have no power of enforcement, no troops to carry out orders, no power of the purse.
Which gets at the ultimate worry about Trump.
Our system of laws depends on not just lowly citizens, but presidents as well, abiding by court rulings. Throughout our history, the Supreme Court has been inserted into national crises, often preventing presidents from doing what they want to do. Indeed, sometimes the Supreme Court's verdicts are not vindicated by history. And yet, presidents have complied with those rulings.
Less than a month into Trump's presidency, many leading lawyers and scholars are worried. Professor Blackman fears that if Trump's nominee for the Supreme Court Neil Gorsuch is confirmed and ends up ruling against the president, the next Trump nominee would be "a crony."
Others wonder what would happen if the mercurial Trump loses the travel ban case or another big one. Would he be so sure of his cause that he would refuse to comply?
That would undoubtedly provoke a constitutional crisis. Refusal to obey a Supreme Court order would normally be grounds for impeachment.
But author Shesol worries that in "our hyper-partisan environment, there's an open question whether the president's own party in Congress would actually stand up and say, 'This is unacceptable. This is grounds for impeachment.' "