Having already blundered into self-inflicted political damage, President Trump seems poised to repeat himself in threatening a second government shutdown over his continued insistence that a southern border wall be built.
In a Sunday interview with the Wall Street Journal, Mr. Trump said that issuing an executive order for the military to build the wall was "certainly an option," if a bipartisan congressional committee failed to reach a deal financing the wall by his new Feb. 15 deadline.
Such a step would certainly generate a critical constitutional crisis, with challenges from defenders of Congress's power of the purse, as described in Article I, Section 9: "No money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law."
A naked seizure of that congressional power of the purse by the chief executive would warrant legislative branch appeals to the judicial branch at the lower levels up to the Supreme Court, under Article II. It specifies in the presidential oath that he "will faithfully execute the Office of the President of the United States, and will to the best of my Ability preserve, protect and defend the Constitution."
Could any court, including the one to which Mr. Trump has appointed the two most recent justices, fail to rule against his usurpation of this congressional power? Such a course of action almost certainly would compound Mr. Trump's political woes, and the threat of impeachment by the same Congress.
The fact that the House of Representatives must initiate the impeachment process might have been a safety net for this president had not his Republican Party lost its House majority in the midterm congressional elections. Now, with the Democrats in control, a Trump impeachment leading to a Senate trial would seem more likely, although conviction, requiring a two-thirds vote in the upper chamber, is much less certain.
No American president has ever been convicted, though two — Andrew Johnson in 1868 and Bill Clinton in 1998 — were impeached. Johnson escaped by a single vote in the Senate, and enough Democratic senators saved Clinton's presidency by holding their noses over his sex scandal and voting against conviction.
In 1974, President Richard Nixon faced impeachment in the Watergate scandal in light of the White House tapes that included a "smoking gun," telling of his talk of bribing the break-in perpetrators for their silence. Senate friends convinced Nixon that resignation was preferable to conviction and greater disgrace.
But whether the supremely self-confident and self-aggrandizing Donald Trump would ever follow the Nixon course seems to be out of character. That is, unless resignation would save Trump family members, also said to be under investigation by Justice Department Special Counsel Robert Mueller in his broadened interest in the Trump political campaign enterprise.
The imprecise Article II, Section 4 reference to "high Crimes and Misdemeanors"' is generally interpreted as whatever Congress in its wisdom says they are at the time.
At any rate, a second government shutdown, and a presidential executive order to build the border wall in defiance of the constitutional separation of powers, could itself be judged to be an impeachable offense.
Such is the price the American democratic system is paying now for the mistake of the founding fathers in allowing the selection of a president by a minority of voting citizens through the Electoral College, three million of whom in 2016 preferred his opponent.
It cannot be disputed that Mr. Trump was duly elected. But the circumstance of placing in the Oval Office a man of such abysmal lack of public responsibility and appreciation for what has made the American experience unique as well as "great," is a national disgrace.
Increased speculation of impeaching Mr. Trump may not be the most practical or popular course for Democrats in their own quest for the presidency in 2020. But his own reckless and divisive behavior nevertheless could in the end result in his premature departure from national power.
For now, the country appears sentenced to endure months or even two years more of a president lacking obvious skills of governance or respect for its machinery, and for our fellow citizens who make it work in the public interest.
Jules Witcover is a syndicated columnist and former long-time writer for The Baltimore Sun. His latest book is "The American Vice Presidency: From Irrelevance to Power" (Smithsonian Books). His email is email@example.com.