Fifty years later, majorities of Americans still believe that John F. Kennedy's assassination was part of a broader plot and that a government cover-up tried to keep the public from learning the truth. But both suspicions have subsided from their peaks.
Sixty-two percent in the latest ABC News/Washington Post poll believe the killing was the work of more than one person; as many also think the government has tried to conceal the facts. But underscoring that these are mainly suspicions, far fewer, 29 percent, feel sure that a conspiracy occurred. The rest call it just their hunch.
Despite their continued appeal, conspiracy theories of JFK's assassination are less common today than in the past. Suspicions about a wider plot peaked at eight in 10 Americans 30 years ago, while the number who suspect a government cover-up topped out at 81 percent in 1993.
More recently, suspicions about a plot have subsided by 8 percentage points, and views of a conspiracy have eased by 6 points, compared with an ABC poll 10 years ago.
The two theories tend to find purchase with the same people: Fifty-three percent in this poll think there was both a conspiracy and a cover-up. Just two in 10 don't believe either theory.
GROUPS - This poll, produced for ABC by Langer Research Associates, finds conspiracy and cover-up theories are equally common across gender, regional, partisan and ideological groups. However, there are differences by income, education, race and age.
Views of a broader plot and government whitewash are 23 and 20 points less common, respectively, among college graduates than non-graduates; 17 and 12 points less prevalent among $50,000-plus earners than those with lower incomes; and 17 and 13 points lower among whites compared with nonwhites.
Among age groups, suspicions the assassination was the work of more than one person peak at 67 percent among 18- to 29-year-olds, who were still a long way from being born when the assassination occurred. Seniors, who were at least 15 years old when Kennedy was killed, are least apt to see a conspiracy, though 55 percent still do.
METHODOLOGY - This ABC News/Washington Post poll was conducted by telephone Nov. 14-17, 2013, in English and Spanish, among a random national sample of 1,006 adults, including landline and cell-phone-only respondents. Results have a margin of sampling error of 3.5 points, including design effect.
The survey was produced for ABC News by Langer Research Associates of New York, N.Y., with sampling, data collection and tabulation by Abt-SRBI of New York, N.Y.