It might seem you’ve heard this one before: A schlubby dude (here, Seth Rogen) improbably wins the heart of a woman (Charlize Theron) who’s out of his league. It’s hardly Rogen’s first time at this rodeo; 2007’s “Knocked Up” is the standard-bearer for this trope.

But the political satire “Long Shot” goes one better: It’s blessed with an ace comic foil in Theron, who out-snarks Rogen in scene after scene. The duo makes a terrifically fun on-screen couple, with the kind of zingy banter (thanks to Dan Sterling and Liz Hannah’s screenplay) found in black-and-white movies pre-dating the term “rom-com.”

Theron is Charlotte Field, the impeccably poised secretary of state for a doofy, former TV-star president (Bob Odenkirk); she nurses hope of filling that seat herself one day. Rogen is Fred Flarsky (the writers didn’t go subtle with THAT one), an unkempt and recently unemployed journalist who quits his job on principle when his alt-weekly is bought by a media conglomerate.

At a fancy party with his well-to-do best friend (O’Shea Jackson Jr., who continues to be a gem in every role), Fred crosses paths with Charlotte, who remembers their long-ago connection. She was his babysitter during Fred’s peak awkward-adolescent phase. So their re-connection is less a meet-cute than a meet-cringe, but Fred’s in luck. Charlotte, drowning in sycophants and bureaucracy-minded bores, digs Fred’s brash sense of humor and lack of social niceties, hires him on as a speechwriter — and gradually falls for him.

It’s one of several implausible plot turns, like a sequence of events in which Charlotte and Fred take ecstasy and go clubbing shortly before she’s called into the office to handle a terrorist incident. But director Jonathan Levine, who shone with early films like “The Wackness” and “50/50” before committing the atrocity that was 2017’s “Snatched,” manages to make even the caricatured bits sing.

Turns out Theron and Rogen have great chemistry, especially when she’s upending his expectations of her (and, by proxy, the audience’s). Theron doesn’t do a ton of comedy, but she’s as good at it as she is at hurling a punch. Fred, who complains at one point that “I’m Marilyn and you’re JFK!,” becomes the target of the type of sex-tape scandal (the subject matter of which seems to be a play on the film’s title) traditionally used to shame women.

“Long Shot” has a raft of comic talent in smaller roles. June Diane Raphael — as Charlotte’s right-hand woman, Maggie — does a splendid, “Veep”-level job of lobbing withering remarks at Fred, whose omnipresent teal windbreaker doesn’t fit with the sleek DC ranks. Jackson Jr. has an unexpected rant at Fred’s ultra-liberal orthodoxy. And Alexander Skarsgård, as a Justin Trudeau-like character who’s into Charlotte, gets a brief but hilarious scene as well.

If “Long Shot” takes an 11th-hour turn into the conventional, well, perhaps it’s a reflection of Fred’s lessons on the campaign trail: Change, idealistic though one might be, is often incremental.