LONG BEFORE Donald Trump said that he was Batman, Sam Humphries began envisioning a dark-horse presidential candidate who blindsided everyone, from pundits to the populace.

The Los Angeles-based Humphries, who has most recently written tales starring the Guardians of the Galaxy’s Star-Lord and the X-Men for Marvel, will be stumping for Image Comics this fall with his creator-owned title “Citizen Jack,” with art by Tommy Patterson. The horror-comedy comic, set to debut Nov. 4, aims to show that dreaming of 1600 Pennsylvania Avenue isn’t so farfetched if you’ve got the right monster in your corner.

“If politics alternately makes you feel terrified and amused, then this is the comic book for you,” Humphries told The Post’s Comic Riffs. He said that the idea for Citizen Jack came to him after he became “enraged, inspired, afraid, disgusted by and in awe of what politics has become in America.”

“Citizen Jack” tells the story of Jack Northworthy, a man who turned to a checkered political career (he was impeached as mayor) after his dream to play professional hockey was checked into the boards of reality. Jack’s life has gotten so low, he can’t even sell snow-removal equipment in his home state of Minnesota (where Humphries is from). But then, a secret demon that has strong mental influence over Jack convinces him that he should set his sights on being the commander-in-chief.

“Jack Northworthy, comes from a long line of political outsiders, dreamers and wackos. Rob Ford, Sarah Palin, Bill Clinton, Ross Perot, LBJ, Ronald Reagan…even Eugene V. Debbs. This is a very long political tradition,” Humphries said of the political figures who helped inspire the creation of “Citizen Jack.”

One political figure “Citizen Jack” is decidedly not based on, Humphries said — despite any similarities as a character who isn’t supposed to have a chance, but the poll numbers just won’t eliminate — is Donald Trump.

“The timing couldn’t be more perfect, but this has been in the works for over a year,” Humphries said. “Why is the GOP letting us talk about Trump? Why does The Washington Post want to talk about Trump? Why am I talking about him…right now?

“These are the questions that drives Citizen Jack,” the writer continued. “Trump could be the next president, or he could flame out next week. Either way, Citizen Jack is bigger than Trump.”

“Citizen Jack is about the dark underpinnings of all elections,” Humphries said. “Can a comic book succeed where McCain-Feingold failed? Probably not, but we’re gonna give it a shot.”

The idea of Marlinspike, the demon pulling the strings behind the scenes in “Citizen Jack,” comes from what Humphries describes as the feelings of some who feel that there is an evil element in politics.

“Is there something about the state of our political system that would attract an ambitious, manipulative demon?” Humphries posed. “It seems likely he’d feel right at home, maybe be more adept at gaming the system than the most seasoned real-life political operatives.”

“What if he decided he wanted a puppet president? What if his candidate was a loudmouth, corrupt politician from the middle of nowhere, with a history of dirty money and sex scandals? Could they pull it off? Under the right circumstances…would we let them?”

Humphries said that he won’t use the world Democrat or Republican, identifying “Citizen Jack” as “nonpartisan in our satire.”

As for how long of a run Humphries sees for “Citizen Jack,” that remains to be seen, but he reminds potential readers that Jack and the Demon behind him are ambitious.

“Just like Jack, we have our sights set on the White House,” Humphries said. “Watch and see how far we go. There is a demon at the heart of American politics. We’re just bringing him out on the comic-book page.”