Bernie Sanders won Maine’s Democratic caucuses on Sunday, US media reported.
The Vermont senator got 64% to Hillary Clinton's 36.
He will accrue 14 delegates from the contest, to Clinton's six.
As Clinton and Sanders faced off in a televised debate in Flint, Michigan, just two days before a crucial primary in that delegate-rich northern industrial state, the self-described socialist had a chance to reply to his critics who claimed he downplayed his Jewish heritage.
"I am very proud to be Jewish, being Jewish so much of what I am," he said.
"My father's family was wiped out by Hitler in the Holocaust.
I know what radical, extremist politics mean.
I learned that lesson as a child when we saw people working in stores with number so on their arms.
I am very proud of being Jewish, it is an important part of who I am as a human being."