This article introduces ranstorpism as a mechanism through which minority organising is excluded in the name of democracy. Drawing on Swedish cases, particularly Sida's 2026 decision concerning Islamic Relief Sweden, it traces how uncertain, selective or misleading claims can move from opinion and expert discourse into institutional knowledge and administrative decisions. The mechanism is described in three mutually reinforcing phases: the creation of suspicion, its normalisation through circulation across media and institutions, and its materialisation in decisions that restrict funding, permits, collaboration and legitimacy while formal rights remain intact. Particular attention is given to information laundering, circular referencing, the elasticity of the category "Islamism", and associative stigma. The article situates these processes within the contraction of civic space for Muslim organisations and examines how liberal-democratic concepts can acquire exclusionary functions when invoked to justify restrictions on participation.