Public Policy Polling found that voters were nearly twice as likely, at 23 percent, to believe the government killed political leaders including Bobby Kennedy and Martin Luther King Jr. to silence them.
The poll found overall that Republicans were far more likely to subscribe to such conspiracy theories.
Overall, 13 percent believe the U.S. government engages in "false-flag" operations, where the government plans and executes terrorist or mass shooting events and blames others, while 70 percent disagree.
Republicans (21%) are more than twice as likely as Democrats (9%) to believe this theory.
Overall, 17 percent of voters believe bankers are working toward eliminating paper currency and forcing most banking online -- only to cut the power grid so regular citizens can't access money and are forced into worldwide slavery.
Nearly one in three Republicans (27%) believe the electronic currency theory while just 10 percent of Democrats agree.
But the most widely believed conspiracy theory is the rigging of professional sporting events. Thirty-two percent of voters agree major sporting events are rigged to increase revenue, and 19 percent say they're not sure.