With 12 million Americans tuning in daily, controversial syndicated radio-show host Laura Schlessinger — known to all as “Dr. Laura” — is arguably the best-known Orthodox Jew in the United States.

Rather, she was.

In a shocking if little-noticed revelation, Schlessinger — who very publicly converted to Judaism five years ago — opened “The Dr. Laura Schlessinger Program” on August 5 with the confession that she will no longer practice Judaism. Although Schlessinger said she still “considers” herself Jewish, “My identifying with this entity and my fulfilling the rituals, etc., of the entity — that has ended.”

And with that, Orthodox Judaism lost its loudest mouthpiece and its most prominent “rabbi,” as it were, with the largest American pulpit — with the exception of, perhaps, presidential candidate Joseph Lieberman.

Syndicated nationally since 1994, Schlessinger has won over listeners with her hard-edged advice and razor-sharp tongue. Yet her brash style, not to mention her espousal of a strict “moral health” code — including controversial condemnations of homosexuality as “a biological error” — put her at odds with wide swaths of the Jewish community. Many found her moralist, black-and-white, you’re-with-me-or- against-me stance to be more representative of Evangelical Christians than of Jews, who were often among her most outspoken critics.

Nonetheless, even Schlessinger’s detractors were shocked by the news. “I can’t tell you how significant this is,” said fellow Jewish media star and “Kosher Sex” author Rabbi Shmuley Boteach, who has sparred with Schlessinger over her comments on homosexuality. “Dr. Laura always equated her morals and ethics with Jewish morals and ethics. That placed the American Jewish community in a real fix; on the one hand, she made Judaism very popular, on the other, she made it vilified and hated by many people.”

“I think Judaism is better off not being saddled and directly associated with Dr. Laura’s means,” he said, adding, “although she is still a Jew.”

Schlessinger’s office said she was unavailable for comment.

Schlessinger began her August 5 program by noting that, prior to each broadcast, she spends an hour reading faxes from fans and listeners. “By and large the faxes from Christians have been very loving, very supportive,” she said. “From my own religion, I have either gotten nothing, which is 99% of it, or two of the nastiest letters I have gotten in a long time. I guess that’s my point — I don’t get much back. Not much warmth coming back.”

Schlessinger even hinted at a possible turn to Christianity — a move that, radio insiders say, would elevate her career far beyond the 300 stations that currently syndicate her show. “I have envied all my Christian friends who really, universally, deeply feel loved by God,” she said. “They use the name Jesus when they refer to God… that was a mystery, being connected to God.”

In her 25 years on radio, Schlessinger said she was moved “time and time again” by listeners who wrote and described that they had “joined a church, felt loved by God and that was my anchor.”

Michael Medved, a conservative, nationally syndicated, radio talk-show host, celebrated the Sabbath with Schlessinger about a year ago. “We had talked about having Shabbat again,” he said. When he heard of Schlessinger’s defection, “My first response was to pick up the phone and try and expedite [the visit].”

“I think it’s a shame,” he said. “Though, of course, she was controversial in some eyes, she is one of the most admired women in America. Having the most admired woman in America speak joyously about Passover, Shabbat and Jewish lifestyle events — all of that was quite wonderful.”

Of her conversion to Judaism, Schlessinger said, “I felt that I was putting out a tremendous amount toward that mission, that end, and not feeling return, not feeling connected, not feeling that inspired. Trust me, I’ve talked to rabbis, I’ve read, I’ve prayed, I’ve agonized and I came to this place anyway — which is not exactly back to the beginning, but more in that direction than not.”

“Was Laura naive to think, ‘gosh, I’ll be the queen of the Jews’? Yes, she was naive,” said Medved. “Part of that comes from not growing up in the Jewish community. It’s so rare to find a celebrity embrace of Jewish religiosity of any kind, I can see why Laura would think her very public embrace would have led to a more enthusiastic reaction. But given all the crosscurrents and controversies that divide our community, I can see why that expectation was wrong.”

In 2001, despite the controversy surrounding her, the National Council of Young Israel honored Schlessinger for her “traditional American values.” Rabbi Pesach Lerner, the executive director of Young Israel, was surprised by Schlessinger’s defection but declined to comment on it.

Born to a Jewish father and an Italian Catholic mother, Schlessinger was raised in Brooklyn in a home that was without religion. Approximately 10 years ago, prompted by a question from her son during a viewing of a Holocaust documentary, Schlessinger, 56, began exploring her Jewish roots.

Yet last week’s revelation was far from the first time Schlessinger has been wracked with religious doubts. Lacking a religious background, she has spent a lifetime searching for that missing something, and “each thing I tried left me feeling empty,” she told Philadelphia’s Inside magazine in 1998. Having already undergone a Conservative conversion in 1997, after a debacle with the Jewish Federation of Greater Dallas — a now-legendary affair in which she allegedly rejected three hotel suites, wouldn’t ride in taxis and offended the entire audience at a $500 plate fundraiser — Schlessinger was tempted to give up on Judaism completely, but decided to undergo an Orthodox conversion instead.

“A large part of me wanted to make a statement after that experience, to stand even taller about Jewish values,” she told the Jewish Telegraphic Agency in 2001. “Besides, if you don’t have an Orthodox conversion, you can’t get buried in Israel. I want to be close to ground zero.”

Rabbi Reuven Bulka, a fellow radio host who presided over Schlessinger’s Orthodox conversion, said he was “stunned” by his friend’s 180-degree turn. “It didn’t make my day, shall we say.”

“She obviously has a tremendous impact,” said the congregational rabbi from Ottawa, Ont. “When she went through the evolutionary stage of her journey, a lot of people were inspired by her own excitement about it. I can’t tell you I know 100 people who became Sabbath observant because of it, but certainly it was a feel-good message for a lot of people. That these feel-good messages won’t be coming anymore is certainly a loss.”

Other Jews within earshot are far from sad to see her go. “I don’t think this is any great loss to the Jewish universe,” said Susan Weidman Schneider, the executive editor of Lilith magazine. “I don’t think she was a particularly effective or useful spokesperson. She doubtless alienated more people than she drew toward Judaism.”

“So, let her say she’s no longer a practicing Jew,” she added. “Let her be just a garden variety, anti-choice conservative.”

“I still see myself as a Jew,” Schlessinger said on the air last week. “But the spiritual journey and that direction, as hardcore as I was at it, just didn’t fulfill something in me that I needed.”

“All I know is, in my experiences with her — which have been considerable — I haven’t known her to do anything less than 100%,” Bulka said. “Anything she did, she did fully. The scary thing is if she said she’s leaving, it’s very forboding.”

“I thought she was a tough little lady — I didn’t think she’d chicken out so easily,” said Rabbi Isaac Levy, the chairman of Jews for Morality, who has staunchly supported Schlessinger’s conservative agenda. “She’s gotten a couple of kicks in the chin and she’s succumbed to it.”

“It seems incredible that an ethicist and moralist of her standing would invoke such shallow arguments,” said Boteach, who was en route to an appearance on the titillating syndicated television show “Blind Date.” “I never got great applause for my work from the Jewish community — but my people are my people, whether they love or hate me.”