Robert P. Jones, the founder and CEO of the nonpartisan Public Religion Research Institute, is author of the exceptionally timely book “The End of White Christian America,” which chronicles the transition of white, Protestant Americans from majority to minority status. In 2009, the country was 54 percent white, Christian; now it is 45 percent. Jones looks at the experience of two main sub-groups, mainline Protestants and evangelical Protestants. (The latter one might recognize as the “hillbillies” from “Hillbilly Elegy.”)