Normally, debates only reinforce already established voters’ dispositions, but Romney needs voters to give him a fresh look and a second chance to make his case.
There are a few instances where voters have used debate performances to make up their minds. Probably the example Republicans like to cite is the 1980 Reagan vs. Carter debate.
Reagan used his well-remembered “there he goes again” line to highlight Carter’s repetition of straw man arguments and his scolding voice. But, Reagan’s close has become a piece of American presidential lore. “Are you better off today than four years ago?” framed the debate and the election for still deciding voters and started a landslide. Reagan had been down in the polls going into the debate.
See Denver Post: Romney refocuses on the economy at Jefferson County rally