Our slow learner in the Oval Office has just received another tutorial in our constitutional separation of powers. The Supreme Court has backed a federal appellate ruling blocking his plan starting next month to deport nearly 700,000 American immigrant “dreamers.”

The decision of the high court, whose conservative majority was strengthened last year by President Donald Trump’s nomination of Justice Neil Gorsuch, has given the beneficiaries of former President Barack Obama’s Deferred Action for Childhood Arrivals (DACA) program at least a temporary lease on life.

The move hands Congress more time to come up with a solution to avoid the mass deportation of young aliens who know no other country as their own, having been brought here as children by their immigrant parents. Most seek a path to U.S. citizenship, and Trump has said he favors it eventually if Congress so rules.

But he has taken no actions to facilitate that outcome. Rather, he continues a verbal assault on American immigration policies, opposing various applicants from certain Latino and African countries seeking family unification and visa preference status. He also continues to press for millions of taxpayer dollars to build his proposed southern border wall.

That notion, oft-rejected by Mexican President Pena Nieto, led to cancellation of a planned visit to the White House after a testy Trump-Nieto phone conversation in which the Mexican leader declined to stop saying Mexico would not pay for the wall.

The current judicial rebuke is not the first delivered to Trump in his brief presidency. Early on, two other federal judges in Hawaii and Maryland said no to him when he ordered a ban on admission of immigration by applicants from certain Muslim countries.

A more recent ruling by the Fourth Circuit Court of Appeals in Richmond, Va., said the ban “denies the possibility of a complete family to tens of thousands of Americans,” an immigration objective derided by Trump and other critics as “chain immigration.” It goes on: “On a fundamental level, the (ban) second-guesses our nation’s dedication to religious freedom and tolerance.” Another Supreme Court ruling, however, has allowed the ban to stand pending review, probably in late June.

Trump’s uncommon relationship with the judiciary branch, as well as with his executive branch Department of Justice, has kept this president either on the defensive or in open hostility toward it almost from the start of his presidency.

First came his firing of FBI Director James Comey, following his reported pitch to Comey to give National Security Adviser Michael Flynn a free pass on lying to the FBI.

Then, when Attorney General Jeff Sessions recused himself in the Justice investigation into Russian meddling in the 2016 campaign, Trump became openly hostile to Sessions, whose recusal prevented him from the power to absolve the president of any malfeasance.

Instead, control of the Justice Departments was passed by Trump to Acting Attorney General Rod Rosenstein, who quickly demonstrated he intended to keep hands off the investigation being pursued by the tenacious Special Counsel Robert Mueller.

Amid all this internal Trump administration turmoil and chaos, the new president chose to declare war on his own FBI in the hands of another Trump appointee, career FBI official Christopher Wray, who so far has proved to be no Trump patsy.

Trump meanwhile charged that certain FBI agents who expressed personal comments favorable to rival Hillary Clinton during the Mueller investigation proved it was stacked against him. He finally felt obliged to have aides say he had no intention of removing either Mueller or Rosenstein from the investigation, which by now had the earmarks of a prelude to an impeachment process against the president.

Why Donald Trump would take this course of waging a running battle against elements of his country’s prime law-enforcement branch boggles not only imagination but common sense as well. He is behaving as if he is a cornered fugitive, not the president of this still-greatest country that he vows to make even greater, but shows every day he is demeaning in his words and actions.