The novelist E.L. Doctorow once wrote, “One cannot consider the U.S. Constitution without getting into an argument with it.” The sparse text of Article II, which establishes the executive branch, especially invites such argument. For one thing, in contrast with Article I, which lays out the duties and limitations of Congress, Article II barely says anything, leaving us to interpret what “executive power” means and what its limits are.

When we look at these two articles, the text and the structure of the Constitution are in tension. Congress has the power of the purse and to declare war, as well as a role in the foreign policy duties of the president (like the requirement for the Senate to ratify treaties). Yet the structure of the government puts the president in a position to both make decisions and articulate them in a way that Congress rarely can. American presidents lag behind their counterparts in other countries when it comes to legislative leadership, as Zach Elkins points out. But viewed through another lens, the presidency is also alarmingly powerful.

Questions about the boundaries of presidential power emerged almost immediately in the early republic — not with Andrew Jackson’s swagger and bank killing, not with Abraham Lincoln and the Civil War, not with the Progressives and the expansion of the administrative state. Our revered first president, George Washington, shaped the partisan debate over the new nation’s relationship with France and asserted the president’s authority to determine the direction of foreign policy with his 1793 declaration of neutrality in the conflict between Britain and France. Thomas Jefferson subsequently resigned from Washington’s Cabinet.

The Neutrality Proclamation example illustrates not only that presidential power has been controversial from the beginning, but also that the use of this power always plays out in a political context. The proclamation challenged some understandings of what the president can do and mapped onto substantive conflicts about the country’s relationships with Britain and France.

Certainly, the courts have sometimes stepped in to limit executive power, creating precedent around concepts like executive privilege, war powers, and the general scope of executive power. But the uncertainty around the bounds of acceptable presidential behavior remains, perhaps nowhere more apparent than in the question of impeachment. Accountability to the electorate, and not constitutional barriers, has served as the main way to place limits on an expansive executive branch.

Amendments to the Constitution have reflected this reality — few have taken on defining the limits of presidential power. A great deal of debate has been devoted to how presidents are selected, as Jonathan Ladd and Seth Masket point out. A few have altered how presidents are selected or leave office — but the text of the Constitution has changed very little with regard to what the president does while he or she occupies that office.

Presidents are now inaugurated in January instead of March, limited to two terms, and empowered to appoint a vice president if that office becomes vacant. They are also, at least in theory, subject to removal if their Cabinet and Congress agree that they’re unfit to serve. But no successful amendment has managed to clarify the conditions under which impeachment is necessary, the scope of presidential foreign policy power, or the proper boundaries between the president and Congress. Sometimes the courts have decided this, but often presidents can do what is politically feasible.

It turns out that is quite a lot.

Presidents can’t usually transform partisan debates or shift the power balances among actors in society. But their proclamations, executive orders, speeches, and military actions all take place against this backdrop, sometimes changing and ultimately reconfiguring political conflicts.

The president is increasingly the focal point of the political system. We know that the politics of the presidency have become highly partisan and that they have always been, well, pretty partisan, especially when issues like impeachment were on the table. The contemporary presidency finds itself at the intersection of a particularly nasty combination: highly personalized politics that also reflect symbolism important to each party, closely divided political contests and declining confidence in political institutions. It’s a perfect storm for partisans to identify with their president, look the other way from abuses of power, and provide no political incentives for other actors to keep the president in check.

Presidents began to build up their own bases of political power, separate from members of Congress or local political bosses, in the late 1800s. This process has now completed, and we are seeing with Donald Trump and congressional Republicans that the president, as the most visible symbol of partisanship that the country has to offer, has substantial sway over the “party in the electorate.”

As of mid-April, the extent to which institutions and politics have constrained President Trump remains an open question. While a number of political scientists have characterized Trump’s White House as weak, he has still used the executive branch, especially the Department of Homeland Security, to enact a set of policies that have affected millions of lives.

Administration critics have expressed fear about a “purge” at DHS and the unchecked power that potentially lies in that department, which was created in the wake of the 9/11 terrorist attacks. And while the administration has suffered a number of setbacks in court, particularly around its changes to immigration and asylum practices, there’s nothing keeping Trump from tweeting about these issues and riling his supporters — or, apparently, from telling border agents to ignore the courts. It remains to be seen how the situation will unfold, and whether restraints are in place or we are in truly lawless territory.

The government structure created by the Constitution allows the president a great deal of power and flexibility. The text does very little to describe the nature of this power or its limits, leaving presidents free to do what they can get away with politically much of the time. In our current political environment, we may be just seeing the beginning of what this means.