This is one of the main problems with polling—some people will feel intimidated into not saying they are going to vote Republican because they may have the impression the pollster will perceive it as a racist decision and an ugly argument will ensue.
I feel that is the true source of the ‘Bradley effect’. It’s known that you will most likely be confronted with hostile and sometimes physical opposition if you say you are voting Republican.
I recall reading an article written by a liberal writer in LA. He performed an experiment wherein he spent the day walking around wearing a pro-Bush t-shirt and cap and then another day wearing a pro-Kerry t-shirt and cap and compared his experiences. He admitted that wearing Republican regalia earned him more contemptuous and confrontational treatment compared with his experience wearing pro-Kerry clothing.
Republican supporters tended to glance at his pro-Kerry attire and glance at his face to assess his person. Pro-Bush attire received shudders, sneers, growled hostile remarks, rude treatment in stores etc.