Barely six weeks into his presidency, Donald Trump has offered the best indication yet of his unfitness to hold the office: his wholly unsubstantiated allegation that President Barack Obama had his phones in Trump Tower wiretapped during the 2016 election.
Beyond the outrageous charge itself, the manner in which it was made, in a string of tweets early Saturday morning over a 37-minute period, raised new questions about his temperament and stability. In that short burst, Mr. Trump charged Mr. Obama with abuse of presidential power worse than "Nixon-Watergate" and akin to "McCarthyism."
Mr. Trump fired his missiles from his Florida luxury resort, where he again had sought weekend refuge from the White House. His attacks against the former president marked a swift return to his accusatory behavior, after receiving much press praise for his conciliatory address to Congress.
In returning aggressively to the offensive, Mr. Trump seemed clearly motivated to divert public attention from the furor over the U.S. intelligence community's finding of Russian meddling in the 2016 election.
First came the resignation of Mr. Trump's national security adviser, Gen. Michael Flynn, for lying about pre-election meetings with the Russian ambassador. Soon after, Mr. Trump's new attorney general, Sen. Jeff Sessions of Alabama, wrongly denied he had met with the same Russian diplomat, throwing the young Trump administration into damage-control mode.
Mr. Sessions pledged to recuse himself from any part in the ongoing Senate and House intelligence committee hearings on the Russian conversations. Mr. Trump himself is said to have been outraged on hearing Mr. Sessions' decision to seek political cover for himself.
All this has evolved from the investigation into what Mr. Trump has called the Russian "ruse." His sudden pivot to his unprecedented allegations against former President Obama, categorically denied by Mr. Obama through close aides, has now raised the dispute to a much higher level.
The charge against Mr. Obama amounts to an allegation of criminal conduct, which if ever proved would invite imprisonment of the accused, and if unproved conceivably could lead to impeachment of the accuser. In any event, the whole incredible circumstance has thrown Mr. Trump's already chaotic presidency into a state of ugly turmoil.
Mr. Trump's accusation reinforces the argument for appointment of an independent prosecutor to establish the validity of both allegations -- of collusion between the Trump campaign and Russian officials, and now of Mr. Trump's unverified bombshell that Mr. Obama wiretapped Trump Tower.
Mr. Trump's impulsive and erratic behavior has in itself elevated speculation over his mental state. Not only Democratic critics but also longtime Republican establishment figures who had begun to accept his election now wonder about his stability in governing the world's most powerful country.
The emergence of former Breitbart News CEO Steve Bannon as Mr. Trump's chief strategist and the administration's fierce embrace of economic nationalism has swiftly heightened apprehension across the political spectrum, at home and abroad.
Mr. Bannon's scary objective -- "the destruction of the administrative state" -- and Mr. Trump's own "America First" slogan have conjured up fears across the Western world that the United States will go it alone after decades of commitment to international economic and military cooperation.
Most notably, these developments come in the wake of Britain's Brexit vote to break from the European Union, and they find an echo in right-wing movements in France and elsewhere, auguring a new era in which America's once-unquestioned leadership is no longer taken as a certainty.
This new period of unanchored drift from democratic principles and political parties is disturbing enough. The stark reality now is that the Western World's hard-won collective democratization is in the hands of an American president afloat in his own self-centered world of narcissism and vengeance.
Perhaps Mr. Trump's latest wild roll of the dice, in charging Obama with illegally spying on him, will somehow begin the unraveling of this most dangerous and unhinged American presidency. If his allegations are quickly proved to be false, more American voters may come to realize the catastrophe that has been visited upon their beloved land. Maybe it's not too late for a legal way out to be found, or least some means to harness this loose cannon against his worst instincts and destructive ways.
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 firstname.lastname@example.org.