The Forward has an interesting story about the majority of prison inmates who demand a kosher meal—and they are overwhelmingly not Jewish:
A number of secular Jews, messianic Jews, Black Hebrew Israelites and, in many cases, people with no Jewish background at all eat a traditional Jewish diet.
Jews, according to one estimate, make up just one-sixth — or about 4,000 — of the 24,000 inmates who eat kosher food in American prisons. And since kosher food can cost more than twice as much as regular fare, it’s costing taxpayers millions to feed all those who want to avoid treyf.
“We want them to be very careful about who they give kosher food to,” said Menachem Katz, director of prison and military outreach at the Aleph Institute, a Chabad-affiliated social services group. “We don’t want them to give kosher food to every Tom, Dick and Harry if they say they are Jewish.”
But here’s the thing: Prisons can’t decide who’s a real Jew.
Beyond it being absurd to think that a warden could answer a thousands-year-old question about who can call himself a Member of the Tribe, it’s unconstitutional for government actors to make “religious decisions.”
The government may not inquire into whether a professed religious believer is recognized by any formal religious body or has beliefs that fit within the majority of the religion that he claims to belong to. If an inmate’s stated beliefs were clearly insincere—for instance, if a prisoner told the warden that he is Jewish but repeatedly told prison guards that he’s a Christian separatist—then the prison could deny the inmate a kosher meal. But, aside from that, the warden can’t get involved in deciding who is a Jew.