IN THE AUTUMN of 1990, Shepard Fairey was broke. He was at art school with people he considered to be far more talented than him, and he felt powerless.

For more than a year, as an in-joke with some friends that later evolved into his well-known “Obey Giant” images, Fairey had been putting up stickers of the French wrestler André the Giant all around town. And at that time, Buddy Cianci was running for mayor of Providence, Rhode Island. He had resigned from that office six years previously, after pleading guilty to assault. A large campaign billboard with Cianci’s campaign slogan, “He never stopped caring about Providence”, seemed ripe for parody, and Fairey stuck a giant version of his André stickers on Cianci’s face.

“It was on the news and in newspapers, and there were all these people discussing whether the prank had merit,” Fairey says. “That opened my eyes that the communication in a public arena doesn’t have to be one-way advertising. People can chime in and make an impact. That was a crucial point for me. Prior to that, I was just doing stickers and punk-rock stuff.”

As for Cianci, he won the election but a decade later was indicted on charges of racketeering, conspiracy, witness tampering and extortion, and he served four years in prison.

In 2008 Fairey targeted another political candidate, but this time the message was positive. The image he created, a simple print of Barack Obama with “Hope” spelled out in bold letters at its base, became one of the most recognisable political images in American history. It also got him into a lot of trouble. After Associated Press accused Fairey of improperly using one of its photographs, taken of Obama in 2006, Fairey claimed he was covered by fair-use laws. He settled a civil case with the news organisation out of court last year, when the two sides agreed to work together with the image, and associated merchandise, and to “collaborate on a series of images that Fairey will create based on AP photographs”.

But last week Fairey pleaded guilty to criminal contempt for misconduct surrounding the case. Having originally claimed to have used a different picture from the one Hope emerged from, he destroyed documents and manufactured evidence. With sentencing set for July, he faces up to six months in jail.

FAIREY MIGHT NOTbe as recognisable as his Obama image, but he has just received one of the ultimate accolades in popular culture. This month, Fairey will guest star in The Simpsonsin an episode titled “Exit through the Kwik-E-Mart”. And next Saturday, as part of the creative festival Offset 2012, he will be in Dublin to speak about his work.

Talking before the court appearance, Fairey was busy and not getting much sleep. He’s working on a collaboration with Jamie Reid, an artist who is known for the imagery he created for The Sex Pistols, and a source of inspiration for Fairey. “The Sex Pistols are a perfect example of how slogans become lyrics and vice versa,” he says. He still views himself as an outsider, and constantly seeks different inspirations.

As early influences, he cites George Orwell’s Animal Farm and 1984 and Ray Bradbury’s Fahrenheit 451 – “books that were about systems of control” – as well as Andy Warhol, Jasper Johns, Barbara Kruger and Noam Chomsky. He surrounds himself with books, magazines and music, cruising the streets to “stimulate myself visually all the time”.

Sometimes he creates his own photoshoots, triggered by an advertising campaign “illuminating the tools of manipulation within the ad”. And he’ll incorporate new patterns in his work, saying he wants to extend his palette even though most people commissioning work from him want something recognisably “Fairey”.

The Hope poster didn’t so much jam the culture as become a part of it. “People say you can oversimplify political movements,” Fairey says – indeed, he was criticised for the imagery he created for the Occupy Wall Street movement – “but the way I look at it is, some people need an immediate, powerful and simple concept to make them look deeper. You can only convey so much with one graphic, but it leads to an investigation.”

Fairey relates this back to one of his own sources of inspiration. Through the rap group Public Enemy he became interested in the Black Panther Bobby Seale and his book Seize the Time. “I think some people who criticise my work are snobbish, as if they’re the gatekeepers to knowledge, to the things we know about society. But I’m a populist. I can’t stand insider elitism or outsider elitism . . . That’s almost like, ‘This is how you’re supposed to be disenfranchised.’ ”

While Fairey’s court case brings into question the roots of the image that made him a street-art star, how he appropriated it and his conduct around defending the image, his Obama poster has been appropriated to the point of cliche. But that is the consequence of creating something iconic, and Fairey knows it. “The way I view copyright is that it’s designed to protect creators from people who . . . would come along and see value in it and create an exact replica,” he says, “That’s copyright to me. Being inspired by something existing is creative evolution.”

Ultimately, he’ll let a lot of things go. “I’d rather spend my time making more stuff than suing people making a few bucks using my stuff. Appropriation is part of my work too. A lot of people would call me a hypocrite if I was suing people.”

He mentions Russian constructivism and punk-rock flyers as styles he has copied, saying, “But hopefully it becomes an aesthetic that’s unique to me.”

As for people who copy Fairey, he refers to that as “solo apprenticeship”, defining it as a way people work with him through his aesthetic without contacting him directly.

FAIREY IS UNUSUALLYopen about how he works. “Sometimes it’s as simple as ripping a headline out of a newspaper. If that’s a spark for an idea, I’ll research the reference imagery to make an illustration. I’ll look through the internet and through books. I might use my wife or my friends for poses. I used to create a sketch with a Xerox machine, but now I use a computer, or I’ll illustrate it by hand and when I’m finished I’ll scan it into my computer . . . If I’m working in flat colour, my computer is the perfect tool to look at things, because there are lots of editing possibilities before I do a screen print. I’ll try to adjust the colour . . . I go through those trial-and-error processes digitally. When it’s time to make paintings, because I’m using collage and spray-painting, there’s a whole analogue-digital back and forth.”

He didn’t foresee the impact Hope would have, “I really looked at that image as any other image I was making.” His motivation was an agreement with many of Obama’s positions, “but I felt I had to approach everything from an outsider perspective.”

Now he views it in a rather understated manner. “I was really happy with how the Obama poster took off. It’s a great example of a grassroots activism that wasn’t fuelled by corporations or a candidate’s deep pockets. I did it as an outsider. When I hear about people complaining about how they’re so powerless, well, yes, the balance of power is disproportionate, but that doesn’t mean you’re powerless. The more people who think they can’t do something in a democracy, the worse off we are. The poster is a thing that I’m proud of.”

He has met Obama “a couple of times” but seems rather nonplussed, “He’s nice enough, a good dude, but he’s always busy so I haven’t had a long conversation with him. I think he’s a decent human being. I know he appreciated the poster, and he sent me a thank-you note. But politicians are not like normal people. They’re thinking about what to say to please people at all times. They can’t be completely honest about their opinion on things, because it’ll turn into a distraction or a controversy.” He pauses, then laughs. “So I could never be a politician.”