A striking poll finding was cited often in coverage of the O.J. Simpson murder trial in 1994 and 1995: Most white people thought the former football star was guilty of killing his ex-wife Nicole Brown Simpson and her friend Ronald Goldman, while roughly the same proportion of black people thought Simpson was innocent. The racial gap in public opinion was one of many elements of the case — along with a long history of conflict between the Los Angeles Police Department and the city’s black residents, and racist statements made by LAPD Detective Mark Fuhrman — that showed race was as important as glove size and forensic evidence.

In the two decades since Simpson was acquitted by a majority-black jury, the racial gap has narrowed significantly. In two recent polls, more than 50 percent of black respondents said they thought Simpson was guilty — up from about 20 percent in most polls before, during and right after the trial.

The more recent polls were conducted in 2014 and 2015, before the case returned to the public eye this year thanks to two high-profile television series: FX’s “The People v. O.J. Simpson” and ESPN Films’ “O.J.: Made in America.” (ESPN owns FiveThirtyEight.) Both series leave the impression that Simpson killed Brown Simpson and Goldman; he has said he is innocent.

Why the shift? Developments in the murder trial and events in Simpson’s life probably have played a role. Changes in demographics and race relations may also have contributed to shifting black opinion about the case.

Right after his acquittal, Simpson vowed to find the real killer. In the 21 years since, no plausible alternative theory has emerged, “O.J.” director Ezra Edelman said. Simpson was found liable for Goldman’s death and for battery of Brown Simpson in a 1997 civil suit. And rather than chasing leads on the killings, Simpson has surfaced in the public eye in unflattering contexts: facing charges of road rage, starring on a prank television show, writing a book that was (or wasn’t) a confession and committing armed robbery, a 2007 crime for which he is still imprisoned.

“Those are factors that may have swayed people’s opinion,” Edelman said.

Another potential factor: The people answering polls today aren’t the same as those polled at the time of the trial. People who weren’t yet born then are now old enough to be polled, and many who answered the mid-’90s polls have died.

People too young to remember the details of the trial might mostly know about it from subsequent media coverage, which often has treated Simpson’s guilt as a given, said Carl Douglas, part of Simpson’s murder trial defense team.

“White folks still control the media,” Douglas said. “So their perspective will resonate the loudest.”

Douglas also thinks race relations and police practices in the U.S., which he thinks contributed to the majority of blacks doubting Simpson’s guilt in the 1990s, have improved since the trial. “Police practices are better in 2016 than they were in 1995,” said Douglas, president of Douglas Hicks Law, a civil-rights, personal injury and criminal firm in Beverly Hills, California.

Not all data corroborates Douglas’s impression. Polls asking Americans if they think police and the criminal-justice system are prejudiced against blacks show that about as many people think they are as did in the mid-1990s.

“Things are still bad now on many levels,” said Douglas, who has worked as a lawyer in L.A. for 36 years. “They were worse then.”

“I do believe it’s better,” Edelman said. “However slowly, we’re going this way.”

Douglas also thinks that as the trial recedes into history, the heat around it diminishes, and Simpson’s role as a symbol for black Americans fades. “I’m sure some segment of those respondents no longer feel that he justifies the intensity of their belief,” Douglas said.

Douglas predicts that the share of blacks who think Simpson was guilty will keep rising. “When you get to 2026, that number will rise,” he said. “When you get to 2036, I suspect that number will be closer still” to the share of whites who believe Simpson is guilty. However, Douglas added, “I suspect until the end of time, until there’s only one beige race, the belief of Caucasian-Americans will always be higher than African-Americans in O.J. Simpson’s guilt.”

Edelman and Douglas wouldn’t say how they’d respond to the poll question today. Edelman is letting his nearly eight-hour-long film depict the complexities of the case in a way his speculation couldn’t. And Douglas said, “O.J. Simpson, for better or worse, believes that once you’re my lawyer, you’re always my lawyer, so I assert the attorney-client privilege.”

“O.J.: Made in America” will premiere at 9 p.m. EDT Saturday on ABC.