Watching the coverage of the New Hampshire primary, we're starting to hear talk about the "Bradley effect" being responsible for Hillary Clinton's victory. The Bradley effect for those of you who don't know is where an African American candidate receives a far lower percentage of the vote than their poll numbers suggested because white voters say tell pollsters they will vote for an African American but instead back the white candidate in the privacy of the polling booth. The Bradley effect was coined after LA Mayor Tom Bradley (an African American) narrowly lost the 1982 California governor's race after polls showed he would win by double digits.
So now we are hearing this again after polls showed Barack Obama would win by double digits and instead he lost by 2 points. There's just one problem: it's not true. Barack Obama received a percentage of the vote that just about corresponded to his poll numbers. However, Hillary Clinton received a far higher percentage than her poll numbers indicated, which suggests that she won undecided voters overwhelmingly rather than voters falsely claimed to back Obama.
Follow me below the thread for more detail.
Huffington Post has a list of polls that were done in New Hampshire after the Iowa results. If you look at the polls, Obama got was averaging 38.7 percent (37, 42, 41, 39, 35, 38, 39) in 7 pre-New Hampshire polls. He got 36 percent when all of the votes were counted, which is well within the margin of error.
In the polls Hillary Clinton averaged 29.3 percent (30, 29, 31, 30, 28, 28, 29) in 7 pre-New Hampshire polls. She got 39 percent, which is a 10 percent jump from what the polls showed she would get. So a better question would be why Hillary Clinton had a much better performance than the polling showed. We know that she won overwhelmingly among women and it would appear that she overwhelmingly won undecided voters. Since there was a much higher turnout, likely voter screens for polls would have excluded new voters since they tend to filter out voters who have not voted in prior elections.
For us to see a Bradley effect, we would need to see Obama's final numbers sharply drop from what polls predicted, which is not what we saw. According to CNN:
Many voters decided on their candidates late in the process, the polls showed, with 18 percent of Republicans and 15 percent of Democrats saying they settled on a candidate on the day of the primary.
If we refer to the polls, only 7-9 percent said they were undecided which suggests there was a big surge among likely voters so a lot of people who made up their minds late showed up. It is very easy for the conventional wisdom to settle on certain factors that decided an election and it is often quite wrong (such as moral values and gay marriage swinging the 2004 election). Before the media starts getting carried away with this narrative, we need to consider things more closely.