God, that's a depressing headline.
According to a Fairleigh Dickinson University PublicMind poll, 63% of Americans who are registered to vote accept at least one political conspiracy theory, though the polls findings show that those with greater knowledge of current events are less likely to buy in to conspiracies...except for Republicans, whose likelihood to believe in conspiracies increases with current events knowledge.
From Fairleigh Dickinson Univeristy:
However, the relationship between current events knowledge and belief in conspiracy theories is conditional on partisanship. Among Democrats, each question answered correctly reduces the likelihood of endorsing at least one of the conspiracy theories by seven points. Among independents, each additional question reduces it by two points. For Republicans, though, each additional question answered correctly tends to increase belief in at least one of the theories by two points.
“There are several possible explanations for this,” said Cassino. “It could be that more conspiracy-minded Republicans seek out more information, or that the information some Republicans seek out just tends to reinforce these myths.”
For the record, the conspiracies introduced to those polled include matters of whether or not President Obama is hiding information about his background (believed by 36% of those surveyed); belief that the government knew about 9/11 before it happened (25%); belief that Bush supporters rigged the 2004 presidential election in Ohio (23%); and belief that the 2012 election was stolen by Obama (19%, including 36% of Republicans and 4% of Democrats).
For the rest of this poll which is practically guaranteed to cause you to feel shame in your fellow Americans, it's available to be viewed here.