Obama’s 2008 campaign had Shepard Fairey’s “Hope” poster; if there’s a defining image for Donald Trump’s presidential moment, it could well be The Forgotten Man, an oil painting by Utah-based artist Jon McNaughton. The detailed image takes some unpicking: In front of a twilit White House, with the American flag at half-mast, all the past presidents of the US are gathered. In the left foreground is a Caucasian man in contemporary dress, sat on a bench, his gaze cast downwards, “distraught and hopeless as he contemplates his future,” as the artist puts it. Closest to him stand (presumably) Abraham Lincoln, Ronald Reagan, Thomas Jefferson and George Washington, who hold out their hands to him as they look beseechingly to the figure on the right: Barack Obama. Obama stands aloof, arms folded, looking away, surrounded by an applauding gaggle including Bill Clinton and Franklin Roosevelt. Founding father James Madison beckons towards Obama’s feet in a “What are you doing?” gesture. Under Obama’s right foot is the US Constitution.

The Forgotten Man, by Jon McNaughton. Photograph: Jon McNaughton

It won’t win any prizes for either artistic merit or subtlety, but McNaughton’s painting has come to national prominence. Donald Trump even obliquely referenced it in his victory speech last week, stating that “the forgotten men and women of our country will no longer be forgotten”. Later that night, Fox News anchor Sean Hannity, a stalwart supporter of both Trump and McNaughton, pulled up a full-screen image of The Forgotten Man on his show. “He’s the one that has been left out,” Hannity explained. “The people of Wisconsin, Ohio, Iowa, the people of Michigan, Pennsylvania and all across this country, they saw this election for what it was: massive government failure … a precipitous decline in this country, and men and women, our fellow citizens forgotten, like that guy on the bench. That’s what this is about.” A few days later, according to McNaughton, Hannity purchased the painting. He plans to present it to Trump to hang in the White House.

McNaughton admirer Sean Hannity, of Fox News. Photograph: Rick Scuteri/AP

Trump will doubtless appreciate The Forgotten Man’s bludgeoned-home political sentiment, but the style of the painting is equally in tune with political zeitgeist. None of Fairey’s hipster pop graphics, thank you; McNaughton’s kitsch realism looks to the past. It winds the clock back to the wholesome, easily legible Americana of Norman Rockwell – which was itself a repudiation of modern art, a retreat into the representational certainties of a time when the US was presumably last great.

One Nation Under God, by Jon McNaughton. Photograph: Jon McNaughton

Before Obama’s presidency, 48-year-old McNaughton was a virtual unknown, specialising in run-of-the-mill landscapes and Biblical subjects. But he took a new, Tea Party-friendly direction in 2009, starting with One Nation Under God, a painting that pretty much sets out the artist’s moral stall. An alternative title might have been “Separation of Church and State, My Ass”. It is a Last Judgment-style composition with Jesus Christ at its centre, holding the Constitution. Behind him is pantheon of patriots, soldiers and religious figures. At his right hand are the righteous modern-day citizens (soldier, mother, doctor, priest), and to his left are the damned, or as the artist put it in his online annotations, “those who have weakened the country”: a judge, a businessman, a news reporter, a lawyer, an actor, a liberal academic holding Darwin’s The Origin Of Species, and a pregnant mother, presumably contemplating abortion.

Con Artist, by Jon McNaughton. Photograph: Jon McNaughton

The Forgotten Man came a year later, and McNaughton has been on a roll ever since. His themes are nothing if not consistent: One Nation Under Socialism depicts Obama burning the Constitution, in The Demise Of America, Obama is literally playing the fiddle while Washington burns. The Con Artist depicts Hillary Clinton with an artist’s palette in an pastiche of Munch’s The Scream – in McNaugton’s view she has “painted a careful picture of herself, but behind the brushstrokes lies the truth”. Even more brazen is Wake Up America, in which Obama gives a stump speech while dollar bills rain down and foreign leaders cheer in the background. The enthralled crowd are oblivious to the fact that they are wrapped in chains – all except our “Forgotten Man” figure, who is hacksawing through the links. McNaughton has denied any element of racism in his work but his images do little to support the claim, especially one depicting the US’s first black president as the literal enslaver of a predominantly white populace.

Wake Up America, by Jon McNaughton. Photograph: Jon McNaughton

American conservatives have routinely worked themselves up into a lather over contemporary art images such as, say, Andres Serrano’s Piss Christ or Robert Mapplethorpe’s explicit gay photography; McNaughton demonstrates they can serve up some offensive imagery of their own, albeit in a fusty, retro style. Robert Hughes might have called it “the shock of the old”. The difference is, neither art critics nor the targets of McNaughton’s brush, take his art all that seriously. It provokes derision and parody more than outrage. But many people clearly do take it seriously – including, potentially, the president elect. If the US is engaged in a culture war, McNaughton’s art represents how far back the front line has been pushed.