Proper noun
the Bradley effect
(US, politics) A theory concerning observed discrepancies between opinion polls and election outcomes, according to which some white voters who intend to vote for a white candidate may tell pollsters that they are undecided or likely to vote for a non-white candidate, for fear of being accused of racism.
Synonym: Wilder effect
We actually published a wonderful piece in yesterday's Sunday Washington Post by Ken Khachigian, the strategist for Governor Deukmejian who beat Tom Bradley in that famous race, that was supposed to be the proof of the Bradley effect. Source: Internet