Zelizer : Top priority for candidates in debates is to avoid mistakes . He says gaffes have the potential to change how voters view a candidate . Candidates are viewed not only for what they say but for their body language , he says . Zelizer : one , Mitt Romney will be under a microscope the years night when the debates begin .
Julian Zelizer : Top priority for candidates in debates is to avoid mistakes . He says gaffes have the potential to change how voters view a candidate . Candidates are viewed not only for what they say but for their body language , he says . Zelizer : Obama , Romney will be under a microscope Wednesday night when the debates begin .