From a NY Times obit [that runs a full half page]:
[He] was a leading proponent of public choice theory, which assumes that politicians and government officials, like everyone else, are motivated by self-interest — getting re-elected or gaining more power — and do not necessarily act in the public interest… He argued that their actions could be analyzed, and even predicted, by applying the tools of economics to political science in ways that yield insights into the tendencies of governments to grow, increase spending, borrow money, run large deficits and let regulations proliferate.
From a Buchanan obit in Forbes
Even the liberal New York Times conceded the unsustainability of our current path, ..in its obituary: ‘Much of what [Buchanan] predicted has played out. Government is bigger than ever. Tax revenue has fallen far short of public programs’ needs. Public and private borrowing has become a way of life. Politicians still act in their own interests while espousing the public good.’
Buchanan’s term for what is happening is ‘Democracy Unchained.’ He noted, ‘Historically, government has grown at rates that cannot possibly be long sustained. In this sense alone, modern America confronts a crisis of major proportions in the last decades of the twentieth century. In the seven decades from 1900 to 1970, total government spending in real terms increased forty times over.’ Ah, 1970. The good old days. Federal spending then? About $200 billion. Today? $3.8 trillion.
Personally, I most remember the yearly conferences he ran at Virginia Tech around a decade ago, mixing economics, political philosophy and philosophy of science*. The presentations were marked by an unusual feature: an invited speaker would not give his/her own paper, someone else would. The author would be given a short time to respond afterwards, followed by lengthy group discussion**. Philosophers, in my experience, resist such a manner of proceeding, but I hope some time to get them to experiment with it.
*Buchanan had been in Economics at Virginia Tech for many years, starting the Center for Public Choice, later moving it to George Mason, ultimately returning to Blacksburg where he lived in a big farm house in the country. He was also an adjunct distinguished alumni professor in the philosophy department at Virginia Tech.
**Jim and his group had also instituted a complicated set of hand signals that participants were to employ in raising questions, which I admit to never having gotten down.