Edwards attacked Clinton Sunday for lacking clarity on a variety of positions.
"I mean, she says she's for ending the war, but she'll continue combat missions in Iraq," Edwards said. "She says she's for standing up to Bush on Iran, and she votes with Bush on the Iranian Revolutionary Guard."
"[She] said that she was not for doing anything with the taxes for social security, and then apparently she told somebody in private that she was. I mean I don’t know."
Edwards was asked by reporters to respond to what Clinton said Saturday night at the Iowa Democratic Party's Jefferson Jackson dinner.
"There are some who will say they don't know where I stand," Clinton told the audience when it was her turn in front of the crowd of about 9,000 Iowa Democrats. "Well I think you know better than that. I stand where I have stood for 35 years. I stand with you and with your children and with every American who needs a fighter in their corner for a better life."
Clinton has come under attack from opponents in recent days over her answer to a question at a debate on whether or not she supports giving driver's licenses to illegal immigrants.
At the time Clinton said the plan “makes a lot of sense" but stopped short of endorsing it.
In his speech in Des Moines Sunday, Edwards also unveiled what he's calling the "Plan to Build One America" book, a printed pamphlet that outlines his various policy proposals.
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-CNN Iowa Producer Chris Welch