In an interview with C-Span on Sunday, Republican presidential candidate and retired neurosurgeon Dr. Ben Carson praised the thoughtful work that Thomas Jefferson put into crafting the U.S. Constitution in 1787. Trouble is, Jefferson wasn't involved in drafting the Constitution, a fact Carson even pointed toward in his latest book, "A More Perfect Union," which says Jefferson was "missing in action" and in Paris, serving as minister to France at the time, the Washington Post reported. [Jefferson was the author of the Declaration of Independence, though the final draft included revisions suggested by others.]

When asked by C-Span to name the most impressive Founding Father, Carson settled on Jefferson. "Oh boy, I'm impressed by a lot of them," Carson said. "But I'm particularly impressed with Thomas Jefferson, who seemed to have very deep insight into the way that people would react and tried to craft our Constitution in a way that it would control peoples’ natural tendencies and control the natural growth of the government.”

Carson has flubbed his Jefferson facts before. Following the Oct. 1 shootings at Umpqua Community College in Oregon, which killed nine people, Carson said in an interview with Fox that “Thomas Jefferson himself said gun control works great for the people who are law-abiding citizens and it does nothing for the criminals, and all it does is put the people at risk." 

Carson also referenced in his book a version of the statement that the website of Monticello, Jefferson's estate, lists as untrue. "This is not something Jefferson wrote, but rather comes from a passage he included in his "Legal Commonplace Book." The passage is from Cesare Beccaria's Essay on Crimes and Punishments," the Monticello site states.

Carson made further headlines Monday for backing fellow GOP candidate Donald Trump's claims that he saw Muslims in Jersey City, New Jersey, celebrating the crumbling of the World Trade Center towers during the Sept. 11, 2001, terrorist attacks on New York City. Carson said he saw video of the celebrations, which many have said did not happen.

"There are going to be people who respond inappropriately to virtually everything. I think that was an inappropriate response. I don’t know if on the basis of that you can say all Muslims are bad people," Carson told reporters, referring to the purported celebrations.