WASHINGTON » In the 1970s, Jack Shaheen, the son of Lebanese Christian immigrants, began his groundbreaking research into how Arabs and Muslims are demonized in American pop culture and, from the start, it was an unwelcome pursuit.

The first academic paper Shaheen wrote on the subject languished, unpublished, for three years. His first book manuscript racked up dozens of rejection letters. Smear campaigns in academic circles painted him as a propagandist. And the work was lonely — nobody else cared about how Rudolph Valentino launched the stereotype of the swarthy, desert-dwelling predator with his 1921 film “The Sheik.”

Still, Shaheen pressed on in what became a lifelong mission to expose what he considers racist and dangerous distortions of Arabs and Muslims. Over the past 40 years, he’s addressed the topic in three books, in a documentary, on two Hollywood film sets and in countless news interviews.

And yet Shaheen paused when he received an invitation to speak last month about media depictions of Muslims before a small gathering on Hilton Head Island, the picturesque beachfront community in South Carolina where he lives with his wife, Bernice. He eventually accepted, but for the first time in his four-decade campaign, he considered saying no.

“I just turned 80 and I didn’t want to have to confront all this bigotry,” Shaheen said by telephone from the island. “I’ve never had anxiety speaking about this issue. I’ve never felt this way before. That’s how strong this bigotry is. There was prejudice before, yeah, but this is bigotry.”

In all his years of research, Shaheen said, he’s never seen anti-Muslim prejudices this intense, including in the aftermath of the 9/11 attacks. The current hostility toward Arabs and Muslims, he said, is reflected in and reinforced by on-screen portrayals that haven’t evolved much over the years.

Shaheen’s list of “worst offenders” is long and includes some beloved box-office hits, such as “True Lies,” with Arnold Schwarzenegger (incompetent terrorists conquered by the American hero) and Steven Spielberg’s “Indiana Jones and the Last Crusade,” with Harrison Ford and Sean Connery (greedy sheikh wants to destroy non-Muslims with missiles).

Children’s films aren’t immune, either — protests from advocacy groups forced Disney to change these lyrics in the opening song in “Aladdin”: “a place where the caravan camels roam, where they cut off your ear if they don’t like your face. It’s barbaric, but hey, it’s home.”

The post-9/11 shift was seen most markedly on the small screen, with the popularity of TV shows about federal agents (“24,” “Homeland” and “The Unit”) in which Muslims continually have their loyalties questioned, Shaheen said. The closest sympathetic portrayal in this genre is the “good Muslim,” a patriot who helps take down “the bad Muslims” and who’s typically presented as an exception, Shaheen said.

It’s no wonder, then, that U.S. public opinion polls reflect a dim view of Islam and Muslims, giving politicians cover for rhetoric that would be universally condemned if directed at African-Americans, Latinos or any other marginalized community, he said.

Shaheen warns that the onslaught of negative images only alienates American Muslims and gives ammunition to recruiters for extremist groups such as the Islamic State, known as ISIS.

He applauded when President Barack Obama mentioned the issue while visiting a Baltimore mosque — “He must’ve read my book,” Shaheen said with a laugh — but grew skeptical again when Secretary of State John Kerry flew to Los Angeles two weeks later to meet with Hollywood executives. The State Department said the focus was to brainstorm ideas for improving the government’s anti-extremist messaging.

“We have no idea what was discussed at that meeting,” Shaheen said. “I would hope that at the meeting he would’ve said that we are really helping ISIS when our politicians and movies vilify Islam. Taken together, there’s a danger that ISIS will use this as a propaganda tool.”

Shaheen said politics is the reason for the glacial pace of change in depictions. For years, he said, entertainment executives shied away from sympathetic roles for Arabs and Muslims lest they be accused of pro-Palestinian bias in the Palestinian-Israeli conflict. Today, it’s al-Qaida and the Islamic State shaping the narrative. And the depictions that once vilified foreigners now extend to U.S.-born Muslims, too.

“When I first started, nobody even recognized the existence of the stereotype because there had been no documentation,” he said. “In the past, you could say there was no awareness. Now there is awareness and, despite that, it persists and endures more than before.”

Shaheen, a self-proclaimed fan of “Quantico,” isn’t calling for a moratorium on storylines involving Muslim extremists, but he wants broader, more nuanced depictions. He said his consultation on two movies — “Syriana,” starring Matt Damon and George Clooney, and “Three Kings,” which also starred Clooney — came about because it was important to the directors that the characters be multidimensional.

ABC’s “Quantico,” about a group of FBI recruits who become embroiled in a terrorist plot, notably depicts twin FBI agents, Nimah and Raina — one veiled, one unveiled — who are shown leading full, complicated lives; headscarf-wearing fans were thrilled when one episode showed the veiled twin swimming alongside her FBI colleagues in a full-body swimsuit.

That sort of attention to getting portrayals right is rare, Shaheen said, but it’s what sustains him in an otherwise bleak moment for Arabs and Muslims on the silver screen. He said Muslim advocacy groups must continue lobbying, in Washington as well as Hollywood, for a cause that remains as unpopular as when he began studying it four decades ago.

“In spite of the doom and gloom, I remain an optimist,” Shaheen said. “I do have faith in the young image makers. To do nothing means the situation will continue. You’ve got to continue moving forward.”