There's a lot of churn in the cult, and it looks like they're losing members and replacing them with immigrants that make an easy mark, having left their entire social structure behind. Doesn't bode too well for the cult, but unfortunately there's always money to be made by exploiting the poor, so if they restructure some I'm sure they'll be able to manage this shift just fine.
It's not much to go on but since there's a comparable drop in the blacks and whites, this seems to indicate something that will probably be pretty obvious to most here - the largest factor at play here is social support. A quick google search turned a comparison of income by race (http://www.infoplease.com/ipa/A0104552.html) which if I'm reading this correctly shows that blacks tend to have a lower household income than both whites and hispanics. If income (which usually tracks reasonably close to education) were a huge factor then I would expect to see the demographics shifting towards blacks and to a slightly lesser extent hispanics. Since it's only shifting to hispanic, that indicates to me that this is more about immigration than education or income.