Zephyr Teachout, a law professor at Fordham University, lost the Democratic primary challenge she mounted against New York Gov. Andrew Cuomo this month. Voters looked beyond the fact that Cuomo has reportedly kept an ethics commission he established from investigating people close to him. Teachout has spent most of her academic career as an expert on corruption law railing against politicians like the governor, without much success. In her new book, “Corruption in America,” she carries on the crusade.

The book is a critique of several recent Supreme Court decisions, especially Citizens United, in which the court repeatedly struck down campaign finance rules set by Congress, holding that campaign spending and donations are not a form of corruption. Teachout objects to the definition of “corruption” the court adopted, and most of the book is an exploration of what that simple word has meant and how the courts have interpreted it throughout the country’s history.

Americans from James Madison to Teddy Roosevelt have used the word “corrupt” to condemn those who let gifts, money and donations do their thinking for them, Teachout shows. Campaign donations, which legislators rely on for reelection, can subtly influence a legislator’s judgment. To prevent what she views as corruption, Teachout argues for a more generous, robust system for publicly funding elections.

This common-sense definition is very different from the one the court used in Citizens United, and it is entirely foreign to life on Capitol Hill. A typical member of Congress devotes several hours a day to asking for contributions and several more to worrying about how her donors will feel about her votes on the floor.

Justice Anthony Kennedy argued that “corruption” can mean only an exchange in which a public official agrees to perform a clearly specified action, or a quid pro quo. Why he and the court agreed to this particular definition is a mystery, Teachout argues. An explicit bribe can be less damaging than donations offered without any strings attached, which still powerfully sway representatives. Corruption is hard to define, and Kennedy was apparently looking for a precise standard — more on that momentarily — but insisting on quid pro quo doesn’t resolve the ambiguity. It is never exactly clear what makes something a quid or a quo.

’Corruption in America: From Benjamin Franklin's Snuff Box to Citizens United’ by Zephyr Teachout (Harvard Univ./Harvard Univ.)

Kennedy and his colleagues, particularly Justice Antonin Scalia, should be embarrassed to read Teachout’s book. Their opinions have done violence to language, discarding two centuries of lay usage and legal precedent in favor of a novel and arbitrary definition of the word “corruption.”

On the other hand, there are contradictions in the broader traditional definition as well that Teachout never fully acknowledges, although the history she relates makes them obvious. We have never quite managed to apply our understanding of corruption in a consistent way, which is why Teachout’s book is filled with colorful anecdotes about Americans getting away with all sorts of chicanery.

The problem is that campaigns cost money, and — absent an effective system of public funding for elections — there can be no democracy without campaign contributions. Citizens give to candidates whose policies they support, whether their reasons for donating are principled or not. Deciding whether a contribution is corrupt is difficult without knowing the motives of the donor.

Historically, Americans have tried to insist that gifts that do not involve appeals to reason, judgment or conscience are corrupt, but corporate lobbyists always have arguments in abundance for a policy if their clients stand to gain from it. Suppose a lobbyist representing investors who hold bonds issued by a troubled municipal government offers a councilman a campaign contribution. The lobbyist then observes that a commitment to repaying the bonds would improve the city’s standing with creditors, solve the fiscal crisis and quickly restore crucial public services for residents, who, after all, are desperately waiting for bold leaders ready to make tough decisions. The lobbyist might be right, but is the donation corrupt? Similar situations arise again and again in Teachout’s account.

Kennedy tried to escape the dilemma by resorting to the worldview of contemporary economics and social science, which studiously ignores people’s motives and seeks only to describe their behavior. Legal scholarship and judicial opinions have incorporated more and more economic concepts over the past few decades, an important trend for understanding Citizens United to which Teachout doesn’t devote enough space.

Economists never ask whether people have good reasons for spending their money on, say, pet accessories. Likewise, the court does not ask whether people have good reasons for making campaign donations. Patriotism, ambition, faith, avarice — all are equally valid reasons for contributing, according to Citizens United.

The quid pro quo standard, which leaves motives out of the discussion, appears to lend the abstract rigor of economics to corruption law. It does not. Legislators and judges are not economists, and while it can be useful for economic analysis to ignore what drives people and focus on how they act, analyzing a problem is not the same as solving it. Policymakers do need to worry about motives, especially the ones that are dangerous to society if left unchecked.

Perhaps we can never truly be public-spirited. Whatever our views on politics are, our private histories and material interests always affect our ideas about what’s best for everyone else in subtle ways. Even so, “Corruption in America” shows that it is possible to establish and maintain governmental institutions that shield us from our worst instincts. This was the goal of Madison and his peers, and it could still be achieved with a better public-election finance system, which could be constitutional under Citizens United if the system did not restrict private donations. Democrats who will be looking for a fresh agenda in 2016 should read Teachout’s book carefully.

Max Ehrenfreund is a reporter on the financial desk at The Washington Post.

CORRUPTION IN AMERICA

From Benjamin Franklin’s Snuff Box
to Citizens United

By Zephyr Teachout

Harvard. 376 pp. $29.95