I'm sure that Brendan Nyhan already knows this paper. But it's not very good news for those of us who hope political debate can be improved by more accurate political information. The message seems to be "Lie often, and go negative early." Reminds of the Christmas card I saw from Jason Reifler
Belief Echoes: The Persistent Effects of Corrected Misinformation
Political Communication, forthcoming
Abstract: Across three separate experiments, I find that exposure to negative political information continues to shape attitudes even after the information has been effectively discredited. I call these effects “belief echoes.” Results suggest that belief echoes can be created through an automatic or deliberative process. Belief echoes occur even when the misinformation is corrected immediately, the “gold standard” of journalistic fact-checking. The existence of belief echoes raises ethical concerns about journalists’ and fact-checking organizations’ efforts to publicly correct false claims.