In interviews, Democratic presidential candidate Bernie Sanders usually does not like to disclose much about his personal life. But when he does acquiesce, he often cities his Judaism as having shaped his political views during his most formative years. 

“I’m proud to be Jewish,” the U.S. senator from Vermont said at a media breakfast hosted by the Christian Science Monitor. But, he added, “I’m not particularly religious.” As a young boy, Sanders said, being Jewish taught him “in a very deep way what politics is about.”

In several interviews, Sanders has recalled how -- after learning he was personally affected by the Holocaust -- he began to understand the role of politics. Sanders told the New Yorker that after World War II, his family received  "a call in the middle of the night about some relative of my father’s, who was in a displaced-persons camp in Europe someplace.” He learned that several relatives on his fathers' side had been killed in concentration camps. Even as a child, he was “very conscious as a kid that my father’s whole family was killed by Hitler.”

“A guy named Adolf Hitler won an election in 1932,” Sanders told the Christian Science Monitor. “He won an election, and 50 million people died as a result of that election in World War II, including 6 million Jews. So what I learned as a little kid is that politics is, in fact, very important.”

Sanders' father, who was a Polish Jew, came to the United States during the Great Depression and raised the family in Brooklyn, New York, where Sanders was born in 1941. Hollywood producer Sid Ganis, who grew up in the same building as Sanders, described their neighborhood as predominately one of “ordinary secular Jews."

“Some of us went to Hebrew school, but mainly it was an identity in that it got us out of school on Jewish holidays,” Ganis said. 

Friends say that Sanders fell among those who identified with Judaism, but was not particularly religious.

“He’s not what you would call rule-observant,” Richard Sugarman, a friend and Orthodox Jew who teaches religious studies at the University of Vermont, told the New Yorker. “If you talk about his Jewish identity, it’s strong. It’s certainly more ethnic and cultural than religious -- except for his devotion to the ethical part of public life in Judaism, the moral part. He does have a prophetic sensibility.”

Sanders spent some time in Israel in his younger years on a kibbutz, but some have made false claims that he has Israeli citizenship. During a National Public Radio interview, host Diane Rehm mistakenly referred to Sanders as a dual U.S.-Israeli citizen, but he corrected her and said the claim was “nonsense that goes on in the Internet.” 

Rabbi Jonah Pesner, head of advocacy and social justice for the Reform Movement, told the Washington Post that it is significant to have a Jewish candidate running for president, even if he is not highly religious.

“What’s significant here is that we have a viable candidate for presidency who is not only Jewish but has a Brooklyn accent, and it’s not a big deal,” Pesner said Tuesday. “And although he is not a particularly public candidate about his faith, he focuses on issues which resonate with the words of the Hebrew prophets. Many of us find language around income inequality very consistent with our own sense of Jewish social justice.”