Each time I visit Los Angeles, where I was raised and where my family still lives, the experience cannot help but be a little bittersweet. As pleasant as it is to spend time with my parents and sisters and to catch up with my friends, every new look at the L.A. Orthodox Jewish community is inevitably disheartening.

Having grown up in an inclusive, tolerant Jewish world that made room for a wide variety of religious practices, moral values, and lifestyles, each return trip is another snapshot in an ongoing series depicting the erosion of the modern Orthodoxy I once knew. The saddest part, for me, is seeing how little-mourned it is.

Take my recent visit for Passover. My father and I went to dinner at a kosher restaurant. Looking around at the other diners, I was struck by the number of people who, through their garb (covered hair and ankle-length skirts for women; black velvet kippot ((skullcaps) and/or black hats for men) signaled their allegiance to right-wing Orthodoxy. Hardly anyone there looked like me, clad in jeans and a T-shirt and a knit kippah of my own. The clothing, always a priminent symbol of difference in the Jewish community, indicated to me that the neighborhood, once a gathering spot for observant Jews of all kinds, was Jewishly diverse no more.

Although I didn’t realize it as a kid, the constricting transformation of the Orthodox world was well underway in the LA of my childhood. Samuel C. Heilman’s new book “Sliding to the Right: The Contest for the Future of American Jewish Orthodoxy,” which traces the religious and cultural battles Orthodox Jews have been fighting for the past 50 years, could serve as a history of my life and the lives of nearly everybody I grew up with. I can attest to the fact that modern Orthodoxy--what Heilman refers to as the “contrapuntalist” mode of Orthodoxy, which seeks to balance the religious and secular worlds--has increasingly ceded ground to what Heilman calls “enclavist,” right-wing Judaism.

This is not to unduly celebrate or valorize my childhood. The schools I attended had their own allotment of teachers and administrators; the synagogues were often rife with venomous internal politics over ritual and policy; and not every classmate I knew had an idyllic Jewish home. The range of religious practice in the community was startlingly wide:among my classmates at Hillel Hebrew Academy in 1991 and 1992 was a boy who took it upon himself to fast every Monday and Thursday, the days the Torah was read with morning prayers, as an extra stricture upon himself, and another whose mother insisted we could not read J.D. Salinger’s “The Catcher in the Rye,” because its racy content made it inappropriate reading material for her impressionable young son.

At the same time, though, Hillel’s rosters included students from less-than-entirely observant homes, where the rules of Shabbat and kashrut were observed more in the breach than in the practice. Many of the boys and girls I attended elementary school with went on to public high schools, and many others were from immigrant families whose commitment to tradition was rock-hard and yet entirely different from that of my American-born classmates, and yet the religious differences, while ever-present, were downplayed in favor of the similarities.

The modern Orthodox world of Los Angeles in the 1980’s and early 1990’s was far from perfect, and far from uniform. But it was precisely that lack of uniformity that kept it alive, and kept it fresh. Full-fledged agreement among my schoolmates, their families, or the community at large about what constituted Orthodox Judaism was rare; and yet, everyone agreed to disagree.

In the 20 years since then, the fragile bonds of the modern Orthodox world have been frayed by an increasingly vocal right wing that refuses to acknowledge or respect any Jewish practice other than its own, and the concomitant exodus from Orthodoxy of all the not entirely observant but Orthodox-affiliated families who made for a diverse, vibrant community. It is less the religious practice that has been affected (although that, too, has been noticeably altered, particularly in its adherence to ever-more stringent forms of dietary regulations) than the surrounding culture; the ideology of Orthodoxy has expanded and hardened, more interested in dictating appropriate behavior than in regulating spiritual affairs.

Modern Orthodoxy has thus become a prescription for proper thinking in every aspect of life from politics (vote Republican, support politicians on the basis of their Israel policy and nothing else) to the choice of profession (law, medicine, or business nothing interesting, please). It has no room for anyone who does not fit the narrowest possible description of Orthodoxy, or who refuses to acknowledge the community’s authority to meddle in every aspect of one’s personal, religious, and social life.

There is a notion in Judaism of putting a fence around the Torah of barring otherwise acceptable actions to protect ourselves from overstepping our bounds and violating the law. For example, we are entreated not to carry, or even touch, money on the Sabbath, to prevent ourselves from momentarily forgetting the rules of Sabbath observance and spending money This previously estimable concept has taken on a disturbingly rigid quality in right-wing modern Orthodoxy, which seeks to wall itself off anything unfamiliar and therefore unsettling.