In this particular election year, anyone trying to craft political fiction that’s stranger than truth faces a difficult task. Yet the creative team behind “Ghost of John McCain” has pulled it off, with a new musical that’s as engagingly daft as it is sprawling despite running only about 90 minutes — all of which are set inside Donald J. Trump’s brain.

It was not always thus, apparently. As reported in the Washington Post, “Ghost” was first conceived by a former Arizona attorney general, Grant Woods, who served as McCain’s chief of staff in the 1980s and eulogized the senator at his funeral in 2018. After Woods died in 2021, a Republican consultant and theater producer, Jason Rose, took the treatment — a “linear” account of a debate between McCain and Trump, as Rose described it — to a playwright and composer whose credits include “Colin Quinn: Long Story Short” and numerous off-Broadway shows, Scott Elmegreen.

The result, which combines Mr. Elmegreen’s book with music and lyrics by Drew Fornarola, is a delirious journey that opens with the recently deceased McCain — played by a handsome, Hawaiian-born actor, Jason Tam — arriving at what he assumes to be the pearly gates, dressed for the occasion in a spiffy white suit (courtesy of costume designer Mieka van der Ploeg, who gets to have a lot of fun here). 

Alas, the snarky receptionist who greets the war hero-turned-congressman, senator, and presidential candidate doesn’t seem to be Peter, and it’s not long before our hero is asking, in the refrain of one of Mr. Fornarola’s playful songs, “Is this heaven or a three-star hotel?”

If the ambience inside this purgatory suggests the latter, McCain is soon greeted there by a steady stream of the distinguished and infamous, both living and dead. They include, in addition to Hillary Clinton — who turns up in a red pantsuit and devil horns — Teddy Roosevelt, Joe Biden, Roy Cohn, Elon Musk, Taylor Swift, Kanye West, Plato, Lindsey Graham, and Sarah Palin. (Barack Obama lurks as well, predictably, though we never meet him.)

There’s also an unspecified “sexy lady Fox News anchor” — asked by McCain if she’s Ainsley Earhardt, she blithely responds, “It doesn’t matter” — as well as fictional characters, from a Hitler puppet to Karen, a nurse and young grandmother from Arizona who turns up in a Trump T-shirt and a MAGA hat, plainly representing the kind of struggling, working-class voter whose disgust with establishment politics made Trump seem attractive. 

When McCain resolves to embark on a mission to “mold Donald Trump into the kind of president I can get behind,” he tries to enlist Karen, played by a bubbly Zonya Love, in a coalition, but she’s skeptical. “You and he promised the same damn thing: That you’d win,” she retorts. “Only difference is, he delivered.”

McCain’s battle, in fact, becomes as much about winning over Karen as it is about saving his own soul; and at points, Messrs. Elmegreen and Fornarola threaten to tip into earnestness. One scene finds McCain locked in solitary confinement, inviting specific comparisons to his time as a prisoner of war.

Yet the show’s creators are, for the most part, too busy being goofy to wax sentimental or, worse, pedantic. While Trump is portrayed, literally, as a spoiled teenager — alternately hyperactive and petulant in Luke Kolbe Mannikus’s amusing performance — Biden comes off as a feckless old man, albeit more endearing; the latter is played by Ben Fankhauser, who also appears as a slimy Cohn and as Mr. Graham, presented here as a flamboyant dancing queen. 

Four of the six cast members, in fact, juggle multiple roles deftly under Catie Davis’s brisk direction. Lindsay Nicole Chambers is pertly witty in parts ranging from Hillary to “Daughter-Wife,” who when asked if she is Melania or Ivanka simply responds, “Yes.” Aaron Michael Ray, droll but reserved as Roosevelt, then brings a booming voice and a hilariously brash presence to Trump’s Brain, who gets a bulky purple costume and his own musical number. 

When Ms. Love isn’t playing Karen, she turns up as a bejeweled Eva Perón — Trump’s fondness for Andrew Lloyd Webber musicals is a running joke, so the title character of another, “The Phantom of the Opera,” is also featured — and, later, Kamala Harris, who makes her entrance while drinking from a coconut.

By this point, the musical’s flimsy fourth wall is pretty much down, and it’s acknowledged that whatever preaching “Ghost of John McCain” has done is to the choir. Still, with its relatively light tone and giddy buffoonery, this show is more of a confection than a sermon.