When the history of Donald Trump’s remarkable political career is written, we should all hope, if only for the sake of American literature, that the task falls to someone like the historian G.M. Trevelyan, who believed that the “dignity” of his chosen profession need not be “afraid of contact with the comic spirit.”

I am praying for the appearance of this masterpiece in my lifetime, but my guess is that before too long, grave chroniclers will be neglecting all the absurdist Trumpian set pieces — his firing of his secretary of state Rex Tillerson via Twitter; his dogged insistence, despite official forecasts, that Hurricane Dorian might hit Alabama, prompting the National Oceanic and Atmospheric Administration to issue a statement supporting his view; Rudy Giuliani’s accusations of voter fraud in the 2020 election, delivered in the parking lot of Four Seasons Total Landscaping — in favor of earnest analysis of the economic impact of withdrawing the United States from the Paris climate agreement.

We have been advised to take Mr. Trump, if not literally, then at least seriously. I do not think we should extend him even that courtesy. We should see him not as a Caesarean figure set upon remaking the United States in his own image or an ideologue who has attempted to impose a coherent philosophical vision on our unruly public life, but as a somewhat hapless, distracted character, equally beholden to vast structural forces and to the limitations of his own personality.

The only thing more remarkable than the rhetorical élan with which Mr. Trump has laid out a revolutionary new agenda for the Republican Party — realist in foreign policy, populist and protectionist in economics, moderate on social issues — is his gross unsuitability for any task more consequential than the lowering of marginal tax rates. On issues ranging from military intervention to health care to the stock market, Mr. Trump is simply the continuation of the G.O.P. establishment by other means. If Barry Goldwater was the book and Ronald Reagan the movie, Mr. Trump is the glitzy jukebox musical.

This understanding of Mr. Trump’s political career is, among other things, the best way to make sense of his recent decision to bomb Iranian nuclear facilities. His dovish admirers reacted with shock, interpreting the move as a betrayal of noninterventionist principles. Republican hawks told themselves that like George W. Bush, with his abandoned vow to avoid nation-building, Mr. Trump had simply evolved.

Both sides assumed far too much ideological intent. His decision is best understood not as a betrayal of principle or the result of a deliberative process of coming around to his opponents’ view, but rather as an expression of his desire to accomplish something — anything.