From the description of the book “Politics by Principle, not Interest” (1998) by James Buchanan and Roger Congleton.
“The very logic of majority rule implies unequal treatment or discrimination. If left unconstrained, majority coalitions will promote the interests of their own members at the expense of other persons. This book focuses on the effects of applying a generality constraint on the political process. Under this requirement, majorities would be constitutionally prohibited from treating different persons and groups differently. The generality principle is familiar in that all persons are to be treated equally. In summary, this book extends the generality norm to politics.
“Several defences of equal treatment or generality are developed and applied. These include the familiar intuition that invokes fairness. But the primary argument here is centred on political efficiency, which is increased when governments are constrained to treat persons or groups generally rather than differentially. The political efficiency defence of the generality constraint is based on a public choice analysis of the implication of majoritarian discrimination.”
The book description also explains that the idea is an extension of Hayek’s argument.
“In his treatise, The Constitution of Liberty (1960), F. A. Hayek emphasized the central role of the generality principle, as embodied in the rule of law, for the maintenance of a free society. This book extends Hayek’s argument by applying the generality principle to politics. Several important policy implications emerge. There are no direct implications to suggest how much governments should do. The argument suggests strongly however, that, whatever is done politically, must be done generally rather than discriminatorily.”
A book worth reading for anyone with an interest in democracy, freedom and other related bits.