His victory Tuesday night in New Hampshire broke a barrier as old as the republic: The Vermont senator became the first Jewish candidate to win a presidential nominating contest.

But even as that path-breaking feat was in touching distance in the days before the primary, and attention increasingly focused on his surging campaign for the Democratic nomination, the Brooklyn-born politician's religion received little mention on the national stage until CNN's Anderson Cooper noted it while moderating a town hall with the Democratic presidential candidates last week.

In part, that's because Sanders, a self-identified democratic socialist, has repeatedly described himself as a secular Jew without strong ties to organized religion. But Jewish political activists, students of history and pollsters say the candidate's minority faith has also been overlooked because attitudes toward Jews in America have evolved to the point where there's no stigma attached to his background.

"In some ways, it's a non-story," said Sandy Maisel, a Colby College professor who tracks the status of Jews in America. "And that it's a non-story is a pretty interesting story."

At the town hall, Cooper pointed to Sanders' faith when an audience member asked about how the candidate would reach out to religious voters.

"You're Jewish, but you've said that you're not actively involved with organized religion," Cooper said. "What do you say to a voter out there who ... sees faith as a guiding principle in their lives, and wants it to be a guiding principle for this country?"

"It's a guiding principle in my life, absolutely, it is," Sanders responded, before offering some rare insight into how he perceives the relationship between faith and governance. "I would not be running for president of the United States if I did not have very strong religious and spiritual feelings."

He described that spirituality as a feeling "that we are all in this together and that when children go hungry, when veterans sleep out on the street, it impacts me."

Hillary Clinton, for her part, has frequently talked about being Methodist and at the town hall said, "I feel very fortunate that I am a person of faith, that I was raised in my church." Clinton added that she receives a scripture lesson every morning, via email, from a minister with whom she is close.

References to faith are also quite common on the GOP side. Billionaire businessman Donald Trump has declared that he has a "great relationship with God," and Christianity is a centerpiece of the pitch Sens. Ted Cruz and Marco Rubio are making to Republican primary voters, especially the evangelicals who make up a crucial part of the party's base.

The reasons Sanders' religion hasn't gotten more attention, however, go beyond his own rhetorical decision. They also speak to the evolution in attitudes towards Jews in American society.

"What we see is that the vast majority of the American public, 80%, say (a candidate being Jewish) would not make a difference in their vote, one way or the other," said Greg Smith, the associate director of research at Pew Research Center, referring to a survey published on Wednesday. "The remainder are pretty much evenly divided between those who say they would be more likely to vote for a Jewish candidate and those who say they would be less likely to vote for a Jewish candidate."

The response led Pew to categorize Judaism in political contestants as being among "traits that are neither assets or liabilities," the same as for evangelicals. By contrast, being Mormon or Muslim was assessed to be a potential difficulty.

Steve Rabinowitz, a veteran Democratic operative, Jewish activist and, notably, a Clinton supporter, describes Sanders' religion as being hardly "noteworthy" -- at least, not outside his own community.

"We are at the point where a Jew running for office is entirely no big deal," Rabinowitz told CNN. "Nationally, we're there. We're so much there that for a lot of Jews the fact that Bernie Sanders does not more embrace his Jewish identity is an issue rather than the idea that he might do better if he hid it more."

Maisel, author of the 2001 book "Jews in American Politics," agreed that Sanders' religion was not a vulnerability.

"I did an interview with an Israeli newspaper last week, who said, 'Isn't this amazing? Aren't people going to vote against him because he's Jewish?," related Maisel. "I said, 'No, they're going to vote against him because he's too liberal."

Or perhaps because he's too secular.

JUST WATCHED Clinton and Sanders argue over who's progressive Replay More Videos ... MUST WATCH Clinton and Sanders argue over who's progressive 02:40

According to Pew, the question of religion versus religiosity yields a more instructive answer than any related to a specific faith. While 8 in 10 said their votes wouldn't be influenced, for better or worse, upon finding out a candidate is Jewish, more than half, 51%, said they would be less likely to support one who "does not believe in God."

Jews themselves, however, don't necessarily see religious belief as key to identifying as Jewish.

A 2013 Pew Research Center survey found that just 15% of American Jewry said being Jewish was "mainly a matter of religion," with the rest listing ancestry and culture as more important.

And while Sanders might not be observant -- as evidenced by his decision to give a speech at the evangelical Liberty University on the first day of the Jewish holiday of Rosh Hashanah -- he told the press at a breakfast hosted by The Christian Science Monitor in June that "I'm proud to be Jewish."

When invoking his religious background, Sanders has sought to make the case that it is one that would help America progress.

After GOP presidential candidate Ben Carson said in October that he could not abide a Muslim president, Sanders delivered a political rebuke wrapped inside a personal history.

"Let me be very personal here if I might. I'm Jewish. My father's family died in concentration camps," he told student supporters in Virginia a few days later. "I will do everything that I can to rid this country of the ugly stain of racism which has existed for far too many years."

Indeed, Sanders is the first self-identified Jew to win a primary. Though Barry Goldwater, who garnered the Republican nomination in 1964, had a Jewish father, he was raised and considered himself to be Episcopalian.

For Rabinowitz, the see-sawing fortunes of former Connecticut Democratic Sen. Joe Lieberman offers further proof that Jewish politicians have become subject to many of the same headwinds faced by their gentile colleagues.

"Al Gore's selection of Joe Lieberman to be his running mate was a big damn deal. It was a big deal in the community. It was a tremendous point of ethnic pride," Rabinowitz said of the 2000 presidential race. "And yet, four years later when he ran on his own for president, he got almost no support."

Lieberman, as a candidate and in office, wore his religion differently than Sanders, a self-described democratic socialist whose liberal politics owe more to the New Deal and union leaders like Eugene V. Debs than any Talmudic imperative.

Despite their different styles, the fortunes of both Lieberman -- an Orthodox Jew who does not work on the Sabbath -- and Sanders, who hews more closely to the cultural and ethnic Judaism that has become a staple of American popular culture, represent a wholesale departure from the era of restricted clubs and hotels that banned Jewish men and women, and from the time when a young senator from Massachusetts had to give a speech reassuring voters that he wouldn't be taking orders from the Catholic Church.

"It's akin to the fact that there are now three Jewish justices on the Supreme Court whereas decades ago, people would have said there's one Jewish seat on the Supreme Court," Nathan Diament, executive director of the Orthodox Union's Advocacy Center, said of Sanders and the changed environment for Jews in politics. "Thankfully, Jews and Judaism are much more accepted as part of American society today than decades ago, where a Jew reaching high levels of leadership is accepted."

It remains to be seen how Sanders would fare in a general election race where the spotlight only glares more strongly on every aspect of a candidate's background, and how his religion would be perceived by a Republican Party that tends to be more focused on faith and receptive to Christian references than Democrats.

JUST WATCHED Bernie's brother predicts big things Replay More Videos ... MUST WATCH Bernie's brother predicts big things 03:29

The same Pew survey found that 64% of Republicans say it's "important" to have a president who shares their religious beliefs as compared to 41% of Democrats.

Diament, however, noted that Lieberman was well-regarded by evangelicals.

And asked what a general election with Sanders as the Democratic nominee might look like, Smith at Pew also pointed to some recent history for guidance.

"In 2012, we saw that there were significant numbers of Americans who had reservations about Mormonism, particularly evangelicals," he said, but he noted that in the end what really mattered was party affiliation.

"If it came right down to it and it was a choice between a Republican, Mitt Romney, who was Mormon, or the Democratic incumbent Barack Obama, the choice was going to clear for them: They may have reservations about Mormonism, but that wasn't going to stop them from voting for Mitt Romney," he said.

Yet even as national politics has come to welcome them, Jewish citizens, who make up only about 2% of the American voting population, remain the most frequently targeted religious group.

According to the most recent FBI statistics, more than 56% of the 1,140 documented anti-religious hate crimes in 2014 were motivated by anti-Jewish bias. In Western Europe, Jews have come under increasing threat from right-wing groups and, in certain high-profile cases, Islamic extremists.

Still, Maisel believes those lingering hatreds, even as they occasionally erupt in spasms of violence, have become an outlier in the broader national culture.

"Anti-Semitism is not a value of the majority of the American people," he said. "So if politicians play to it, that's a losing strategy."