People with cognitive impairments are regularly denied access to the vote in democraticnations. At the same time, the accuracy of legal regulations is uncertain due to thevariety of legal classifications and the vague administrative procedures envisaged for theirimplementation. This article offers an extensive analysis of the accuracy of legal restrictionson the vote for people with cognitive impairments in all electoral democracies. The articleargues that the prospect of ever regulating the vote accurately, in the sense of avoidingboth misclassifications and arbitrary administration of restrictions, is difficult to envisage.In the face of the regulatory problems associated with the attempt to restrict the votefor people with cognitive impairment, it is concluded that enfranchisement of all adultcitizens would constitute an improvement.