This trend toward Catholic and Jewish appointments is significantly a function of self-selection: Evangelicals for a number of reasons are less likely to plot career paths that would qualify them for SCOTUS. “Judaism and Catholicism have extremely long and rich legal traditions, while Protestantism generally, and evangelicalism specifically, does not,” historian Elesha Coffman noted in a 2010 Christianity Today report.
Law school was historically a favored path for Catholic and Jewish immigrants hoping to gain respect, legal security, and middle class status in America, while a strain of anti-intellectualism grew among evangelicals. Those evangelicals who value education often favor Christian colleges, which don’t burnish the resume for a SCOTUS pick. Indeed, Protestants of all sorts are now dramatically underrepresented in the Ivy League, from which every current justice hails. Evangelicals also tend to be of lower socioeconomic class and wary of debt, which together can put costly degrees out of reach. Meanwhile Jews, Episcopalians, and mainline Presbyterians hold three of the top four spots for household income among American religious groups.
All this means the pool of qualified Catholic and Jewish candidates is simply larger. Any president’s short list today is likely to have more Catholics and Jews than Protestants, let alone evangelicals.