[cnn-photo-caption image=http://i2.cdn.turner.com/cnn/2011/images/08/30/costello_vert.jpg width=200 height=230 align="right"] From CNN's Carol Costello: Imagine a 2012 presidential race that pits Barack Obama against Herman Cain, hey, anything is possible.  Many political talking heads pooh-pooh the polls.  They claim Cain is just "flavor of the week." Larry Sabato of the University of Virginia calls Cain a "place holder" for voters unhappy … Continue reading Talk Back: Why is Herman Cain surging in the polls?