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Washington CNN —  

Lincoln Chafee is making a bid to be Hillary Clinton’s anti-war foil on the left.

The former Rhode Island senator and governor who this week launched an exploratory committee to seek the 2016 Democratic presidential nomination blasted Clinton’s “lack of judgment” on foreign policy in an interview with CNN’s Dana Bash on “State of the Union” on Sunday.

He said he and Clinton agree on most domestic policy issues, but “have some big areas of disagreement internationally.”

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Chafee all but declared his candidacy, saying: “I want to be on the stage in November, December and January debating these issues.”

His biggest problem with Clinton, Chafee said Sunday, is her vote in favor of President George W. Bush’s war in Iraq.

“That was a moment where the premise for going to Iraq was so false that there were weapons of mass destruction, she didn’t do her homework. We live with the ramifications,” Chafee said. “You may say that’s 12 years ago – that’s a big motivator for me running. If you show a lack of judgment, lack of doing homework then, what can we expect in the future?”

He also blasted her tenure as President Barack Obama’s first-term secretary of state.

Her time as America’s top diplomat, Chafee said, “was kind of a muscular, top-down, unilateral, too close to neo-cons, too Bush-like.”

It ended, he said, with “precious few” accomplishments.

Chafee also said he’ll court the liberal backers of Massachusetts Sen. Elizabeth Warren, who has said she won’t challenge Clinton, pointing to his opposition to Bush-era tax cuts as evidence that he’s focused on income inequality.

“There’s no doubt that Sen. Warren’s absolutely right about what’s happening to the middle class,” Chafee said. “She’s just been a prophet about this for a number of years.”

Chafee was defeated for re-election to the Senate, where he had served as a Republican, by Democrat Sheldon Whitehouse in 2006. He was elected to one term as Rhode Island governor as an independent in 2010. Chafee later became a Democrat, and then ultimately chose not to seek re-election in 2014 when his fundraising and poll numbers lagged behind his challengers.

He defended his party switch, saying it was the GOP that evolved.

“Certainly the Republican Party changed and I never changed,” Chafee said. “As I became an independent my values never changed whether it’s on fiscal responsibility, environment or using government tools to help the less fortunate.”