That's a damned good question.
If these polls purport to be an accurate representation of the populace, that would mean hundreds of thousands (if not millions) of people switched their opinion twice over a few day period.
I just don't buy it. These polls are rigged.
I’m sad to say it but my sister is one of those people. She’ll vote for whoever talks to her last. It’s infuriating.
(I always make sure that I talk to her last :) )