When debates about Islam acquire importance in the public sphere, does the far right adhere to traditional racist arguments, risking marginalization, or does it conform to mainstream values to attain legitimacy in the political system? Focusing on the aftermath of the 2015 terrorist attacks in France, I explore the framing of Islam, discussing how the far right’s nativist arguments were reformulated to engage with available discursive opportunities and dominant conceptions of the national identity. By looking at actors in the protest and the electoral arenas, I examine the interplay between the choice of anti-Islam frames and baseline national values. I offer a novel mixed-method approach to study political discourses, combining social network analysis of the links between seventy-seven far-right websites with a qualitative frame analysis of online material. It also includes measures of online visibility of these websites to assess their audiences. The results confirm that anti-Islam frames are couched along a spectrum of discursive opportunity, where actors can either opt to justify opposition to Islam based on interpretations of core national values (culture and religion) or mobilize on strictly oppositional values (biological racism). The framing strategy providing most online visibility is based on neo-racist arguments. While this strategy allows distortion of baseline national values of secularity and republicanism, without breaching the social contract, it is also a danger for organizations that made “opposition to the system” their trademark. While the results owe much to the French context, the conclusions draw broader implications as to the far right going mainstream.