content: Its due to the increase of non-religious and/or unaffiliated groups. You're looking at 20-30% on average, of each state's population being non-religious or unaffiliated. See here: http://www.pewforum.org/religious-landscape-study/religious-tradition/unaffiliated-religious-nones/ Hispanics are overwhelmingly Catholic, although the primary immigrant group from Mexico to the US is Mestizos (White-Amerindian) not Castizo (White-White).  Given that most states' population demographics (for now) are White, Hispanic, or Black. I would put my money down on Whites (Millennials most likely)  being the ones growing the non-religious//unaffiliated demographics the most, rather than a sharp decline of whites in most of those states. Arguably White Christians of certain denominations have been accelerating this behavior, as anyone who is not immediately a true-believer is shitcanned in their church at lightspeed and no longer welcome, which IMO has probably accelerated the growth of non-affiliated or non-believers and turned some into hardcore anti-theists/anti-religion. Both groups are visible in Voat posts and comments on a regular basis when Christianity (and other religions are brought up).  Since I'm from a "Fire and Brimstone" Baptist area, ironically I'd say White Christians are the reason for the decline in White Christians. Turns out if you treat your own people (whites in this case) badly they won't want anything to do with you.