Americans who follow presidential politics and governance have been riveted for more than a year on this question: What did, or didn’t, Russia do to disrupt the 2016 presidential campaign cycle and the election itself? That’s a backward-looking question, and we continue to trust that special counsel Robert Mueller will solve the puzzle — no matter how ambitiously President Donald Trump tries to clutter Mueller’s path with denials, obstructions and distractions.

This week, though, forces all of us to confront a much different and more urgent question: Does Trump’s stupefying conduct during and after his meeting with Russian strongman Vladimir Putin in Helsinki signal incompetence and obsession that put his presidency, if not this nation, at elevated risk?

Trump struck us as bewildered, bedeviled. He repeated Putin’s self-exoneration despite the well-evidenced accusations of meddling from the U.S. intelligence community. But this was the real subtext: Trump was cutting off any suggestion that he was elected illicitly.

In this setting more than in any before it, Trump’s top priority — reiterating that his campaign didn’t collude with Russians — betrayed the depth of his obsession with an election outcome now 20 months in the past. Faced with the options of looking like Putin’s poodle or admitting that Russian meddling might have made some difference in the outcome, Trump made the worse choice — while standing with arguably the greatest enemy of the U.S.

In Monday’s joint appearance with Putin, and in his peripatetic retellings of Helsinki in the days since, Trump animated his usual self-aggrandizement with a lights-and-sirens display of self-defense. On Tuesday, he contended that in Helsinki he had misspoken. On Wednesday, he continued to play down the significance of his flip-flopping.

This week, the perception of instability and obsession looms over the White House as never before in this presidency. What domestic or geopolitical move will the man in the Oval Office make next? Might that act be reckless, damaging, irreversible?

Because the longer Donald Trump preoccupies himself with Russia and his legitimacy as president, the less legitimate he looks to Americans.

FROM AN EDITORIAL IN THE CHICAGO TRIBUNE