> The religion does not allow for conversion to the faith. If a Mandaean man or woman marries someone who is not part of the religion, the couple’s children are not considered to be Mandaeans.
That’s interesting. Seems like the religion is “doomed” to forever remain that of a small and shrinking minority.
That's obviously not inevitable, seeing as that the population of Mandaeans grew and existed for more than a millennium. It just sets a constraint between fertility and the rate of outside marriage.
They do marry other Jews or descendants of converts from other courts, they just don't marry converts or convert using their own courts. Therefore they are not a real endogamous population.
Also, the edict is only since 1937, they were accepting converts earlier than that. So fundamentally they aren't a success story - they haven't been doing this very long.
Other Jews can marry in, but even this is limited. The majority of self-identifying Jews in the US would not have the qualifications to marry in. Any how, they are an insular community.