This article is part of our latest Museums special section, which focuses on the intersection of art and politics.
SAN FRANCISCO — A towering persona stands in the police criminal evidence warehouse here: a 6-foot-5, clay-and-silicone sculpture depicting a naked Donald Trump, with grotesquely exaggerated features, including a protruding belly.
The police seized the statue during the presidential campaign in August 2016 when Indecline, an anonymous activist art collective, caused a sensation by placing figures in prominent public spots in San Francisco, New York, Seattle, Cleveland and Los Angeles.
The collective said it planned to grab headlines again this year with its most ambitious schedule yet of illegal street displays.
Indecline’s agenda goes beyond presidential politics. Other subjects include gun violence, with a display scheduled for Las Vegas, scene of a mass shooting in which 58 people were killed and more than 800 injured at a concert in 2017.
It would be an audacious, possibly offensive act in a city still recovering from the tragedy, but it is emblematic of Indecline. The group, which had troubling beginnings, has evolved after nearly two decades to become celebrated for political art, even though the artists themselves are unknown.
“Indecline’s body of work is predominantly illegal activities, virtually all of them felonies,” said the group’s spokesman, who declined to give his name. “That’s the predominant reason we stay anonymous.”
In recent years the artists removed commercial billboards to turn them into tents for homeless people in Oakland, Calif., and transformed a suite in Manhattan’s Trump International Hotel and Tower into a rat-infested presidential jail. After the deadly 2017 white supremacist rally in Charlottesville, Va., Indecline hung clownish Ku Klux Klan effigies from a tree in a Richmond park.
Ron English, the contemporary artist nicknamed the godfather of street art, called Indecline “the Beatles of political art.”
“They are this new thing that’s taking something that has been done for millennia and making it fresh and new and capturing a new market, bringing it to a new generation,” Mr. English said.
The art itself is fleeting, typically removed by the authorities shortly after installation. The K.K.K. exhibit in Richmond, for example, was cordoned off as a crime scene almost immediately.
The Trump statues in 2016 were seized within hours, although the San Francisco version remained in the city’s Castro neighborhood for an entire day. The local police declined requests to view the statue in its current lockup, where it remains even though the district attorney and city attorney ultimately decided not to press charges.
“It’s in a secure location,” said Officer Robert Rueca, a San Francisco Police Department spokesman.
With so little public display time, Indecline’s work often gets wider exposure via the news media. The group also photographs and videotapes its work to distribute on social media.
“These things aren’t meant to really stay up very long,” said the artists’ spokesman. “Much of this is built for the day of instantaneous posting and social media, so it lives indefinitely on the internet.”
Heather E. Dunn, a professor at the Institute for Doctoral Studies in the Visual Arts in Portland, Maine, said Indecline represents a hybrid of artist and activist known as “artivists.”
“It’s a way to engage the masses that maybe wouldn’t go to a museum,” Ms. Dunn, an expert in street art, said. “It’s a way to bring art to them. It’s a way to bring a political message to them. In a lot of ways, I find that street art is more powerful than just about any other art that’s being made at the moment.”
Ms. Dunn said that even though illegal art created on other people’s property had long existed, street art with a more political focus gained momentum in the United States in the 1980s, when new laws in places like New York changed graffiti from a misdemeanor to a more serious crime. The art became a de facto antigovernment act.
Now, with heightened security and surveillance, the decision by some artists to be anonymous is an additional act of resistance. “It’s really hard to remain anonymous in the culture that we have right now,” Ms. Dunn said. She noted other street artists doing similar political work, like Denis Ouch in New York and Plastic Jesus in Los Angeles.
Indecline’s anonymous status is due, in part, to a dark past. The group was born amid outrage and legal strife with the 2002 video “Bumfights: A Cause for Concern.”
As young men, the group’s four original members encountered homeless people in Southern California and Las Vegas, and “we created this shockumentary,” Indecline’s spokesman said.
“We start filming the going-ons of the homeless community, which for us was this really eye-opening experience,” he said. “Like, people are pulling their teeth out with pliers because their teeth hurt, and they’re drinking, they’re fighting, they’re doing whatever. It’s insanity. And so ‘Bumfights’ was supposed to be kind of a wake-up call.”
Instead, the video was widely condemned as exploitative and demonizing. Scenes depicted homeless men performing seemingly dangerous stunts and acts of cruelty and violence for the camera. But the video became a sensation when promoted by radio’s Howard Stern, and 300,000 copies were sold at about $20 each.
The filmmakers, Daniel Tanner, Zachary Bubeck, Ryen McPherson and Michael Slyman, faced lawsuits and criminal charges. Plea bargains and settlements followed. The collective today consists of new members scattered across the country, but two of the founders remain active in the group, according to the spokesman.
Indecline has not monetized its notoriety on the scale of other street artists like Shepard Fairey or the anonymous Banksy, whose works can sell for millions. Instead, the spokesman said that collective members have jobs to support themselves, and that the group takes donations and sells merchandise to help fund projects.
Still, there are signs that Indecline could be headed toward a more mainstream future.
Two German galleries recently displayed a version of the Trump prison cell. The collective is producing a documentary about resistance art, featuring prominent artists, like Mr. Fairey. There’s also a satirical political play planned for September and a book in the works.
If all of that does not sound abrasive enough for Indecline, well, “This year we’re also going to try to team up with PornHub, and we’re going to direct our first porno,” the spokesman said. “A political porno film.”
Will it feature Stormy Daniels, a pornographic film actress linked to Mr. Trump? “She’s definitely someone we’ll be contacting,” the spokesman said.