James McGill Buchanan, the political economist who died in 2013, had a hand in some of the most important ideological developments in the American right in the 20th century. From the 1950s to the late 1990s, when a spat with the influential billionaire Charles Koch led to his retirement, he was seemingly everywhere. Starting with Brown v. Board of Education, which he abhorred, Buchanan helped jumpstart the resistance to integration and the right’s embrace of school vouchers; worked to reduce the power of unions and the public’s trust in the government and the welfare state; and assisted Pinochet in Chile and the Kochs in America.

Above all, he was a theorist who believed that democracy and liberty—defined as free market capitalism—were incompatible and that it was necessary to limit participatory democracy to protect the property rights of the extremely wealthy. Though he did no empirical work, he was remarkably influential in the field of public choice theory, which essentially argued that markets could never fail and governments always did.

Four years after Buchanan’s death, he is largely forgotten—but his vision of a government with little power over schools, housing, or health care, toiling in the shadows of wealthy individuals and corporations, is closer than ever to being realized. Thankfully, the historian Nancy MacLean has documented Buchanan’s influence over both the Kochs and contemporary politics in a remarkable new book, Democracy in Chains, which argues that the radical right revolution engineered by Charles and his brother David is not just about accruing political and economic power, but about restricting democracy itself.

Democracy in Chains exposes the frightening intellectual roots of the radical right, as well as its ultimate ambition: to erode American democracy. I spoke to MacLean, who teaches at Duke University, about Buchanan’s remarkable life, the “velocity of change” that has occurred in America over the past six months, and how Donald Trump fits into all of this. This interview has been edited and condensed for clarity.

James Buchanan has largely existed in the shadow of Milton Friedman, despite the fact that both won the Nobel Prize in Economics. How did you first encounter his work? Why do you think it has largely flown under the radar?