There is a segment of “The King,” Eugene Jarecki’s documentary about Elvis Presley as a metaphor for America, sort of, in which Ashton Kutcher complains about fame.

You may reasonably wonder what Ashton Kutcher is doing in a serious-minded documentary about one of the biggest pop-culture icons in American history. And the answer seems to be that he has no particular reason for being there, other than that he is famous. “The King” is like that, all over the place in a glorious-mess kind of way, rendering it uneven and entertaining in almost equal measures.

But then Kutcher says, almost under his breath, that he became uncomfortable with fame because he knew that he hadn’t done enough to truly earn it. What do you know? Something actually revealing and relatively profound. Jarecki backed into it, but it’s there. The whole film works in much the same way.

The movie revolves around a gimmick. Jarecki got hold of Presley’s 1963 Rolls-Royce Phantom V and tricked it out with cameras. He drives it from one critical location of Presley’s life to the next — Memphis, New York, Las Vegas, etc. — and puts famous and less-than-famous people inside and films them talking about Presley and his impact, or singing songs.

Sometimes it’s moving. The great songwriter John Hiatt gets in, sits down and begins to cry. Emmylou Harris talks about how trapped Presley must have felt by fame, by pressure, by the selfish and self-serving choices made by manager Colonel Tom Parker.

Other appearances are head-scratching. Why is Alec Baldwin there, giving a hard time to fans who want selfies? The only reason seems to be that Baldwin plays President Donald Trump in cameos on “Saturday Night Live.” And Jarecki spends a good bit of the movie hitching what he sees as the decline of the United States to Trump’s star.

It’s an intriguing notion. As Ethan Hawke points out, at every turn when he had to make a choice, Presley chose to follow the money, and while he got rich, it was almost never the right decision. He jumped from Sun Records to RCA for more money, and his sound smoothed out. He signed the biggest movie contract in history at the time but was trapped making horrible films. He wanted to tour after his remarkable TV comeback in 1968, but Parker insisted he set up shop in Vegas and let fans come to him.

He went from a raw, unpredictable, exciting source of inspiration to a greedy, bloated caricature of himself, dead of a heart attack at 42, a victim of his own wretched excess.

Jarecki sees similarities in the country, and yes, Trump plays a part in the story. Who better epitomizes the notion of commerce over art more strongly? Who else measures value by worth to such a degree? Merging these ideas isn’t always a comfortable fit, but it’s a fascinating one.

The best interviews tend to be the ones with writers. Greil Marcus and Peter Guralnick both have tied Presley and other artists into the larger culture that shaped them, and that they shaped. They’re a natural for the film.

So is Public Enemy’s Chuck D, he of the famous “Elvis was a hero to most/He never meant s— to me” lyric from “Fight the Power.” Now, however, he’s a little more forgiving, noting that cultural appropriation — to which Jarecki pays some attention — is the story of America. Van Jones is also interesting, talking about how his father hated Presley. He questions Jarecki as to why he feels the need to rescue Presley’s reputation on the cultural-appropriation front.

Indeed, “The King” is one of those films that we sometimes see being made while they’re making it. The Rolls breaks down a few times. David Simon, creator of “The Wire,” tells Jarecki that one of Presley’s Cadillacs would have been a better fit for the film, and the story he’s telling. It’s a messy movie in that way, but somehow that works, too. After all, the story of Presley is also messy. As is the story of America.

Bill Goodykoontz, Gannett