Great Analysis from RCP
"The second [thing to note from the debate] was Hillary's bad performance. Everyone has off days but this one was special, in that it revealed not a gaffe, which can be explained away, but a potential character flaw. "Wafflers" don't do well in presidential politics -- not only because voters don't like panderers -- but also because a waffler is perceived as someone not tough or honest enough for the presidency. One only has to remember some key ads from past presidential races - Nixon's windmill ad against McGovern or Dukakis's tumbler ad against Gephardt - to realize that the charge is a hard one to shake. It's going to be especially hard for Hillary because it plays into negative gender stereotypes, as unfair as they are. And, it cuts into one of her greatest assets - her intelligence - because she is now beginning to appear to be "too clever by half."
By the end of the debate it was clear Hillary didn't want to offer a definitive answer on anything. She will HAVE to do better or potential supporters will look elsewhere for a candidate whose beliefs they can actually, you know, pin down.