Paul Manafort’s recently concluded trial on charges of tax fraud and bank fraud brought to light some details of the erstwhile Trump campaign chairman’s lavish lifestyle: $1.26 million in designer suits, properties in New York City and the Hamptons, and a string of luxury cars paid for in cash from offshore accounts. While the Manafort example is far from typical, it does vividly illustrate the fact that in the United States today, it is possible to make not just a living but a very good living from electoral work. The most successful political consultants today are compensated similarly to partners at law firms. The industry has its own professional organization (the American Association of Political Consultants) and its own awards show (the Pollies), and exports its product around the globe (including to the former Soviet republics that were the source of much of Mr. Manafort’s income).

Adam Sheingate’s Building a Business of Politics lays out a richly detailed history of the way we got to this point. Drawing from a combination of primary sources, contemporary accounts, and political science research, the author traces the development of the political consulting industry from its origins as an obscure offshoot of the nascent fields of public relations and public opinion in the early twentieth century to its present-day position of near-complete dominance over American campaign activity.

Sheingate identifies two key institutional changes that gave the industry its initial formative spark and then, several decades later, piled kindling onto the flames. The first was the weakening of the agenda-setting power of party organizations brought about by Progressive-era electoral reforms. The institutions of the ballot referendum, the recall, and the primary election for candidate nominations were intended to allow the will of the people to express itself more directly, without the intermediation and gatekeeping of corrupt party bosses.

The second part of that objective—breaking the grip of the party machines—was a smashing success, but the first part was hampered by the fact that different forms of agenda control can lead the same will of the same people to very different outcomes. Referenda in particular gave an opening to practitioners of the then-emerging field of public relations, who found it much easier to mold public opinion on specific issues about which the typical member of the public had little information and weak prior attachments than to move more deeply rooted partisan loyalties. Combined with the ability to shape the agenda directly by placing alternatives on the ballot, this proved a hugely valuable tool for interests with the funds needed to pay for the requisite signature gathering and publicity campaigns.

Sheingate’s view of consultants as supplanting or substituting for party organizations is not entirely novel; Larry Sabato argued in his 1981 The Rise of the Political Consultants that consultants weakened parties by providing a locus of campaign expertise that was independent of party structures. Sheingate’s contribution is to tie this growth of consultants at the expense of party bosses back to its underlying institutional source. It is no accident, the author argues, that the industry first emerged in something like its modern form in California, where Progressive electoral reforms had gone farther in weakening party organizations’ grips over the alternatives presented to voters than in other states.

The second institutional change on which Sheingate focuses attention is the campaign finance reforms that emerged in the aftermath of the Watergate scandal. Particularly consequential, he argues, were the new rules that required itemized disclosures of campaign expenditures and threatened penalties for improper use of campaign funds. In defining what, exactly, constituted proper and improper campaign expenses, the newly created Federal Election Commission (FEC) delineated several categories of campaign services—among them polling, media buying, and direct mail—that were accepted as prima facie legitimate and required no further justification. Outsourcing these tasks to specialized third-party firms greatly simplified campaigns’ accounting and minimized the chances of facing an audit.

This new regulatory environment encouraged the growth of dedicated political firms, which consolidated the market for tasks that had previously been performed by a hodgepodge of campaign staff, unofficial advisers, and side projects of commercial advertising and market research firms. Sheingate’s key insight is that the FEC’s effort to expose the inner workings of campaigns encouraged the shifting of campaign work outside of the campaign organization itself and into privately owned intermediary firms, where it once again became opaque to the prying eyes of regulators. This adaptation, of course, came with a cost to candidates in the form of reduced control over the content of campaign messages and the conduct of campaign activities.

This line of thought—on the consulting industry’s consequences, rather than its causes—leads Sheingate into the book’s most speculative territory, but also some of its most interesting. In the concluding chapter, he wrestles with the implications for American politics of the existence of a class of privatized, profit-motivated campaign service professionals.

One cannot help but notice in Sheingate’s descriptions of the work of early consulting firms a distinctly rightward tilt. Industry pioneer Campaigns Inc’s successful (and lucrative) public relations campaign against the scourge of “socialized medicine” stands out, but time and again we see consultants working to defeat left-wing proposals or candidates that might have cut into their corporate clients’ profits. This ideological asymmetry persists in the industry today: My own work with Zac Peskowitz has shown that firms that work for Republican candidates earn higher markups than do firms that work for Democrats.

In somewhat crude economic terms, consultants and the services they provide are a means of substituting capital for labor in the production process of electoral competition. It is hard not to draw the conclusion that the vanishing of the old ward heelers and block captains and their replacement by paid mass media as the dominant electoral expense therefore privileges the interests of the owners of capital over those of the owners of labor. Although individual consultants are an ideologically diverse lot, a system of campaign services provided for profit inevitably produces stronger inducements to work in politics for those whose ideological commitments align with wealthy interests.

Sheingate’s careful historical analysis shows that the development of a business of politics in its present form was not an inevitable consequence of advances in mass communication technology. Rather, its formation was enabled and its growth accelerated at key points by institutional developments. A hopeful interpretation of this institutional rather than technological origin story is that, of course, institutions can be changed. A Manafort-free world is possible.