WASHINGTON — (CNN)  Lincoln Chafee formally announced his presidential bid on Wednesday.

He has been elected to office as a Republican senator and an Independent governor. Now he’s got his sights set on the White House as a Democrat.

“I enjoy challenges and certainly we have many facing America. Today, I am formally entering the race for the Democratic nomination for president,” he said.

A defining issue for Chafee has been the war in Iraq; he was the lone Republican to vote against authorizing the war as a senator in 2003. Hillary Clinton was among the Democrats to vote in favor of giving President George W. Bush the authority to invade.

Chafee announced he is running for president at George Mason Center for Politics & Foreign Relations in Arlington, Virginia.

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