ideological subgroups failed to update their beliefs when presented with corrective information that runs counter to their predispositions. Indeed, in several cases, we find that corrections actually strengthened misperceptions among the most strongly committed subjects.
-- Brendan Nyhan and Jason Reifler, When Corrections Fail: The persistence of political misperceptions, Political Behavior, http://www-personal.umich.edu/~bnyhan/nyhan-reifler.pdf