Voters have so much information coming to them from the internet now, plus numerous news stations on all the time, every day, they can change their mind at any time. Before information was so prevalent, they got news once a day in the evening from the major news agencies, ABC, CBS, NBC, and daily newspapers. They didn't change their mind much then, but now do. Cable news started the change, and the internet made the big difference, plus phones able to give them news minute by minute wherever they are. This makes polls not as reliable as they were even a few years ago. At this point, I don't believe any poll is reliable.