… is from page 87 of my late Nobel laureate colleague James Buchanan’s March 1988 Virginia Law Review article, co-authored with Geoffrey Brennan, “Is Public Choice Immoral? The Case for the ‘Nobel’ Lie,” as this article is reprinted in James M. Buchanan, Politics as Public Choice  (2000), which is volume 13 of the Collected Works of James M. Buchanan  (original emphases):
Public choice – the hardheaded, realistic, indeed cynical model of political behavior – can be properly defended on moral grounds if we adopt a “constitutional perspective” – that is, if the purpose of the exercise is conceived to be institutional reform, improvements in the rules under which political processes operate. This perspective requires that we shift attention away from the analysis of policy choice by existing agents within existing rules, and towards the examination of alternative sets of rules. Improvement, or hope for improvement, emerges not from any expectation that observed agents will behave differently from the way the existing set of incentives leads them to behave, but from a shift in the rules that define these incentives. The public choice theorist does not envisage his “science” as offering a base for “preaching to the players” on how to maximize welfare functions. His task is not the Machiavellian one of advising governors, directly or indirectly, on how they ought to behave. His task is that of advising all citizens on the working of alternative constitutional rules.
DBx: Jim Buchanan repeated the above description of public choice many times in many different places and in many different ways. And his own, long career was true to this description. Buchanan was no political operative. He spent very little time in the corridors of political power. The vast bulk of his bulky corpus of scholarship is highly abstract and accessible only to those with knowledge of advanced economics. Agree or not with it, Buchanan’s emphasis was typically on the effects of constitutional (or ‘higher-level’) rules on the incentives of the individuals operating under these rules.
Buchanan’s support for free markets and constitutionally limited government had nothing to do with any hypothesized wish to further enrich elites; anyone who knew Jim roars with laughter at any suggestion to the contrary. Instead, his support for free markets and constitutionally limited government emerged directly from his understanding that such institutions are, among all feasible institutions, the ones most likely to ensure for ordinary men and women the best possible lives. Perhaps Buchanan’s institutional assessment is mistaken. It’s fair and appropriate to challenge that assessment with reasoned argument and empirical analyses. But it’s unfair and inappropriate for someone, such as Nancy MacLean, whose assessment of the likely consequences of free markets and constitutionally limited government differs from Buchanan’s, to thereby accuse Buchanan of having evil and underhanded motives.