The endorsement matters not only because of his connection to the Kennedy legacy, but also because Kirk is a former Democratic National Committee chairman and a superdelegate who can vote for Sanders at the Democratic convention this summer. Hillary Clinton has a strong advantage among her party's superdelegates, who played a key role in selecting the nominee in 2008.

Kirk, a longtime aide and confidant to Ted Kennedy, was appointed temporarily to fill Kennedy's Senate seat after his death in 2009. Scott Brown won a special election to complete Kennedy's term a few months later.

HANOVER, N.H. — Bernie Sanders received the endorsement of former Massachusetts senator Paul Kirk on Thursday night at Dartmouth College.


Appearing with Sanders before a rally, Kirk called Sanders "a forthright son of Brooklyn" and praised him for standing up to the influence of big money in politics by opposing the Supreme Court's Citizens United decision.

"The American people are sick of the old way," Kirk said. "They also believe — as Bernie and I do — enough is enough."

"He's tapping into the energies and interests" of disenfranchised and frustrated voters, but is doing so "in a more hopeful way," unlike the Republican candidates, Kirk said. Only Sanders, he added, is providing "outspoken and courageous leadership."

Sanders called Kirk's backing "just another indication of the momentum our campaign has."

In 2008, Kirk, a resident of Marston Mills, backed Barack Obama over Clinton in the Democratic presidential primary. Kennedy also backed Obama over Clinton.

An attorney, Kirk led the Democratic National Committee from 1985 to 1989.

Michael Levenson can be reached at mlevenson@globe.com. Follow him on Twitter @mlevenson. James Pindell can be reached at james.pindell@globe.com.