WASHINGTON • It is campaign season, and facts are taking it on the chin. Republican Donald Trump is not alone among the candidates in distorting the truth, according to fact checkers.
Ms Carly Fiorina falsely claimed the United States was preparing to accept 250,000 Syrian refugees; Mr Marco Rubio said that welders earn more than philosophers; and Mr Ben Carson stated that no signatories of the Declaration of Independence had elected-office experience.
Democrats have stretched the truth as well - Mrs Hillary Clinton by claiming that her handling of e-mail through a private server was "permitted" by the State Department. Mr Bernie Sanders overstated the evidence by asserting that "climate change is directly related to the growth of terrorism".
Such claims, which have been debunked by fact checkers, are part of political life. But the Republican campaign has been notable for incendiary claims.
MOMENT OF UNTRUTH
Republican candidate Jeb Bush claimed that "Florida led the nation in job creation" while he was governor - a statement given a "four Pinocchios" rating as false by the Washington Post's fact checker.
Mr Ted Cruz maintained that Hispanic unemployment and teen unemployment have gone up under President Barack Obama, even though FactCheck.org found statistics showing the contrary.
Mr Ben Carson - who repeated Mr Donald Trump's claim about people cheering on 9/11 - also erroneously claimed that US border patrols released many people attempting to enter the country who were from Iraq, Somalia and Russia, when FactCheck placed the figure arriving from those countries at less than one per cent of the total.
Ms Carly Fiorina ignited ire by claiming that the women's health provider Planned Parenthood was "butchering babies for body parts", claiming the existence of video evidence that has not been located.
"There is no rigorous way to quantify deception being better or worse over time," said Dr Brendan Nyhan, a Dartmouth College political scientist who follows fact-checking and campaigns. "But I do think it is fair to say Donald Trump is on the verge of melting down the fact-checking sites with what he is saying."
Mr Trump earlier this year said the US unemployment rate was as high as 42 per cent. More recently, he tweeted a graphic showing that 81 per cent of white homicide victims were killed by blacks.
The website PolitiFact said the correct figure from the Department of Justice statistics was 15 per cent.
Asked by Fox News about the mistake, Mr Trump said: "I didn't tweet, I retweeted somebody that was supposedly an expert... am I gonna check every statistic?"
The stubbornness surprises even the fact checkers.
Mr Bill Adair, a founder and contributing editor of PolitiFact and a journalism professor at Duke University, said: "There have definitely been times when I scratch my head wondering how could they say something when it is so obviously false and then not acknowledge that it is false."
Boston College political scientist Emily Thorson said "misinformation" can often have lingering effects, even if a falsehood is quickly corrected. For example, if people are told a restaurant has an infestation, they might feel squeamish about the place even if they learn it was a mistake.
"It is hard to undo the initial effects," she said. "Misinformation gets out there and gets repeated."
Dr Thorson's research on the topic showed that when people hear negative things about a candidate which turn out to be false, a correction only "mutes" the impact.