This chapter is intended to elaborate on the existing academic literature addressing the migration of constitutional ideas. Through an examination of ongoing efforts to enshrine “defamation of religion” as a violation of international human rights, the author confirms that the phenomenon of migration is not restricted to positive constitutional norms, but rather also encompasses negative ideas that ultimately may serve to undermine international and domestic constitutionalism. More specifically, the case study demonstrates that the movement of anti-constitutional ideas is not restricted to the domain of “international security” law, and further, that the vertical axis linking international and domestic law is in fact a two-way channel that permits the transmission of domestic anti-constitutional ideas up to the international level. In reaching the findings presented herein, the chapter also adds to the universalism–relativism debate by demonstrating that allowances for “plurality consciousness” on the international level may in certain instances undermine fundamental norms previously negotiated and accepted as authoritative by the international community. From this perspective, the movement in favor of prohibiting “defamation of religion” is not merely a case study that helps to expand our understanding of how anti-constitutional ideas migrate, but also indicative of a reenergized campaign to challenge the status, content, and stability of universal human rights norms. A final version of this article is available for download through the publisher: http://www.emeraldinsight.com/books.htm?issn=1059-4337&volume=56&chapterid=1943488&show=abstract.