Quinn notes that "there was one ethnic group, however, for whom Reuben expressed lifelong dislike and distrust—the Jewish people." According to Quinn, Clark kept several copies of "The Protocols of the Elders of Zion" in his personal library and shared it and other anti-Semitic publications with colleagues and acquaintances. He expressed anti-Semitic attitudes in "code words publicly and in specifics privately" and used his church position to obstruct what he perceived as "Jewish influence." After Nazi Germany's annexation of Austria, Clark denied desperate pleas by Austrian Mormon converts from Judaism who sought the church's help in emigrating to safety.