The Bradley Effect Has Disappeared

Even though national polls have widened slightly in the remaining days of the campaign, concerns about the reliability of the polls in predicting the election of our first African American president won't go away.
According to the Bradley or Wilder effect, white Americans will exaggerate their willingness to vote for a black when asked by poll takers. The theory is that some whites think that voicing support for the black candidate is more socially acceptable.
The most thorough analysis of the phenomenon finds that the Bradley effect disappeared about 15 years ago, and that Bill Clinton and Joe Biden may have help bring about its demise.
Daniel Hopkins of Harvard pulled together the data from 133 statewide elections held between 1989 to 2006 and found that the effect had disappeared about 12 years ago. Before 1996, blacks "performed on average 2.7 percentage points worse than their polling numbers would indicate," an effect that subsequently vanished.
According to Hopkins, racially charged issues like welfare and crime became less important to voters. If so Bill Clinton and Joe Biden may have set the stage for Barack Obama with the passage of welfare reform and crime bills in the 1990s:

In 1995, 12% of Americans cited social welfare issues as the nation's most important problem, a figure that was just 5% by 2001 and 4% in 2004 (Baumgartner et al., 2006). In 1994, 29% of Americans cited crime as the nation's most important problem, a figure that had dropped to 9% by 2004.

Joe Biden's 1994 crime bill, which provided funding for 100,000 police in state and local jurisdictions, helped reduce national crime rates and took away the argument that Democrats were soft on crime. The next year, Bill Clinton joined with Republicans in congress to reform welfare, by placing time limits on benefits and requiring that recipients return to work within two years.
Gone are the days when Republicans like Ronald Reagan could campaign on welfare queens living off the taxes of hard working whites. Not that McCain and Palin aren't trying...
Update: I'll be talking about polls with Allan Loudell of WDEL, 1150 AM, this evening at 5:05 PM.
Second update: I have a longer piece on this subject up at the Guardian.