Republican-turned-Democrat Lincoln Chafee joins 2016 US race

 Lincoln Chafee, a former US senator and Rhode Island governor who was a longtime Republican before switching to the Democratic Party, launched his 2016 presidential campaign on Wednesday, AFP reports.

Chafee, 62, becomes the fourth major politician to join the Democratic nomination battle, insisting in a low-key foreign policy speech at a Virginia university where he announced his bid that he will be "waging peace" if he wins the White House.

"I enjoy challenges, and certainly we have many facing America," he said, stressing that if American leaders show sound judgment "we can fix much of what is ailing us."

"I'm also running for president because we need to be very smart in these volatile times overseas."

Chafee will be an underdog in the nomination race, which is led by frontrunner Hillary Clinton but also features liberal Senator Bernie Sanders and former Maryland governor Martin O'Malley, the political figure who reportedly pushed Chafee to switch political allegiances.

With just one percent support, according to a RealClearPolitics poll average, Chafee is already hitting Clinton, his former Senate colleague, for her 2002 vote authorizing use of force in Iraq.

A Republican at the time, his was the only GOP vote against the war, and in April he argued to The New York Times that the next president "should not have voted for that war."

On Wednesday he took another swipe, saying "we have to repair our credibility" around the globe starting with the diplomatic corps.

He said he advocates for fair international trade, an end to "extrajudicial assassinations by drone strikes," and for allowing fugitive former National Security Agency contractor Edward Snowden to return home.

Chafee has a distinguished political pedigree. His father was a Rhode Island governor, as was his great-great grandfather and a great-great uncle.

Chafee took over from his father, Republican US Senator John Chafee, when the father died in 1999. Chafee was elected in his own right the following year, serving one term, during which he was consistently rated as the Senate's most liberal Republican.

He has consistently backed abortion rights and same-sex marriage, raising the minimum wage and higher taxes on the rich.

He registered as a Democrat in 2013.

The Democratic National Committee described Chafee as a "welcome addition" to the race.

"As a former Republican, Lincoln Chafee can help make the case that his old party no longer represents the best interests of the American people," DNC chair and congresswoman Debbie Wasserman Schultz said.