Former Rhode Island Gov. Lincoln Chafee announced on Wednesday his bid for the White House, painting himself as the as the "international diplomacy" candidate.
His case included criticizing Democratic front-runner and rival Hillary Clinton for her vote for the Iraq War. He was the only Republican senator in the country who voted against authorizing military force.
He also had a list of suggestions for how the U.S. could begin working more closely with the international community.
"Let's join the rest of the world and go metric," he said. "It will help our economy."
He's not the first to make the suggestion, and critics in the past have argued the costs of transitioning to the metric system from what we use today could be high, but he argues the benefits would outweigh that in the longterm.
Chafee used to be a Republican, appointed to the Senate in 1999 after the death of his father.
He's since split with the GOP, becoming the governor of Rhode Island as an Independent in 2010 and later joining the Democratic Party in 2013.
"I don't think anybody should be president of the United States that made that mistake," He told The Washington Post in April. "We live with broad, broad ramifications today — of instability not only in the Middle East but far beyond and the loss of American credibility."
Aside from Clinton, Chafee joins a Democratic field that also includes populist firebrand Bernie Sanders and former Maryland Gov. Martin O'Malley.
While the field is small, like other non-Clinton candidates, Chafee's still seen as a long shot.
An ABC/Washington Post poll from May had Chafee as the Democratic candidate of choice for just 1.4 percent of Democratic and Democratic-leaning registered voters.