In any middle school civics class you’ll learn that the system of checks and balances is a central tenet of the U.S. Constitution. Over the last 100 years, however, it appears the government has been operating under different assumptions, particularly where trade policy is concerned.

The power to regulate commerce and make trade agreements has been the exclusive privilege of Congress since the Constitution was created in 1787. Since the 1930s, this separation of powers weakened as successive presidential administrations have been granted the authority to negotiate trade agreements and modify tariff rates by proclamation rather than by congressional approval. In The Rise and Fall of Fast Track Trade Authority, Todd Tucker and Lori Wallach chronicle this trend, focusing on “fast track,” a trade delegation mechanism established by President Richard Nixon in the mid-1970s.

The book illustrates how executive branch encroachment has oscillated back and forth over many administrations. Tucker and Wallach divide more than 200 hundred years of American history into five broad policy eras to demonstrate this shift. In the first phase, from 1789 to 1890, tariff legislation was under complete congressional control. It was during this time, they argue, that America industrialized and became a developed nation. In the next three periods, Congress went back and forth between delegating and reasserting control over trade policy. In 1934, for example, it passed the Reciprocal Trade Agreements Act (RTAA), which granted the executive branch the authority to unilaterally dictate tariff rates. As a result, Presidents Harry Truman and Franklin D. Roosevelt proclaimed dozens of bilateral trade agreements dealing with tariffs, quotas, and customs regulations, as well as the controversial GATT agreement.

Conversely, there was no delegation of trade authority during the late 1960s and early 1970s as concerns over executive branch unilateralism grew.

Fast track, the most recent policy phase, expanded on previous delegation mechanisms by allowing the president to set U.S. policy on non-tariff and non-trade issues under the guise of trade negotiations. The Trade Reform Act of 1973 granted fast track powers to President Nixon for the first time even in the midst of the Watergate scandal. Fast track circumvented congressional approval processes, allowing the president to diplomatically legislate on issues that had nothing to do with trade. In short, it turned the system of checks and balances on its head by making the legislature answerable to the president.

From 1973 to 2008, successive administrations continuously renewed fast-track, though not without significant congressional wrangling. The mechanism enabled the passage of many contentious trade agreements such as the WTO, NAFTA, and CAFTA. Moreover, the renewal of fast track in 2002 was a major part of George W. Bush’s campaign platform.

In a revised, post-election edition, Tucker and Wallach write that the Obama administration has the opportunity to replace the fast track mechanism once and for all. Rather than renew an outdated policy suited for the realities of the 1970s, they argue, the administration should introduce a new delegation mechanism that addresses the complexities of international commercial agreements in a globalized world without compromising the founding principles of American democracy.