Unreasonableness and Heterogeneity in Buchanan's Constitutional Project

The limitations Buchanan places by his own admission on the project of constitutional political economy are what concern Stefanie Haeffele and Virgil Henry Storr. Along with abstracting to the relative uncertainty of interests of the constitutional moment, Buchanan proposes the ability to restrict the contract’s agreement to unanimity among the “reasonable” and suggests that excessive heterogeneity among the contracting agents could frustrate the attempt to find a mutually acceptable social order. As limiting circumstances for the applicability of constitutional political economy, these restrictions curtail its value in what, as Haeffele and Storr point out, are precisely those circumstances (intractable disagreement among diverse individuals) in the real world where the need to find livable rules to structure political activity is most pressing. These caveats also threaten to subvert the normative and justificatory effort to constrain the scope of political activity to what can attain constitutional consent. Absent a non–post hoc unambiguous notion of when disagreement becomes not only unreasonable but also excludible-unreasonable, or in the case of a proposed social and political community that possesses too few commonalities to share a single political order—neither of which they find provided by Buchanan—Haeffele and Storr see these as ready-made facades for political tyranny.