Everyone who follows American politics is going to spend a lot of time thinking about presidential and judicial power over the next few years. But to really understand the coming clashes between the president and the courts, and the constitutional environment in which they’re taking place, we have to pay attention to what isn’t happening in our system of government almost as much as to what is.

Congress is not doing its job, and the vacuum that its dereliction has created is encouraging presidential and judicial overreach. Congress’s weakness is our deepest constitutional problem, because it is not a function of one man’s whims and won’t pass with one administration’s term. It is an institutional dynamic that has disordered our politics for a generation. It results from choices that members of Congress have made, and only those members can improve the situation. It is hard to imagine any meaningful constitutional renewal in America unless they do.

A weak Congress is not the norm in the American system, and a Congress this weak would surely have surprised the authors of the Constitution. They were far more concerned about excessive congressional strength, worrying it might muscle out the executive and the judiciary. “In republican government, the legislative authority necessarily predominates,” James Madison wrote. Looking around at the 13 state governments in the late 18th century, he observed that “the legislative department is everywhere extending the sphere of its activity, and drawing all power into its impetuous vortex.”

Yuval Levin: What is wrong with congress (and how to fix it)

The growth of American government and the complexity of modern life gradually empowered our presidents and the tangle of administrative agencies that surrounds them. But that did not mean that Congress had to fade into the background. Into the late 20th century, the national legislature aggressively asserted itself, extending its oversight powers over a growing administrative state and battling presidents for preeminence. When the courts got drawn into constitutional battles, they tended to revolve around personal rights and the reach of the Fourteenth Amendment, while struggles over the structural Constitution and the separation of powers were generally wars between Congress and the president. Even in the late 1980s, scholars of our system could warn of an imperial Congress and a fettered presidency. And in 1995, Republicans under Newt Gingrich were determined to use their new congressional majorities to keep the president constrained.

The reasons for the subsequent decline in Congress’s stature and assertiveness are complex, but some of the very measures Gingrich took to consolidate power on Capitol Hill contributed to the trends we are witnessing now. Gingrich advanced an almost-parliamentary model of the House of Representatives. He empowered the speaker and majority leader at the expense of the policy-focused committees, and set in motion a process that robbed most members of the opportunity for meaningful legislative work. His moves dramatically accelerated what was by then a 20-year trend toward the centralization of authority in the hands of congressional leaders. House leaders of both parties have pushed further in that direction in this century, and the Senate has largely followed suit. These efforts were intended to make Congress more effective, but in practice, they rendered most legislators almost irrelevant.

As a result, many ambitious members of Congress have concluded that their path to prominence must run not through policy expertise and bargaining in committees but through political performance art on social media and punditry on cable news. Our broader political culture has pushed in the same direction, encouraging performative partisanship. And the narrowing of congressional majorities has put a premium on party loyalty, further empowering leaders, and leaving many members wary of the cross-partisan bargaining that is the essence of legislative work.

Because it has become less capable of functioning as a venue for legislative negotiation, a centralized, party-disciplined Congress has naturally come to understand itself as ancillary to the presidency. These days, when Congress is in the hands of the president’s party (as it has been at the beginning of every new presidency since Bill Clinton’s three decades ago), it tends to recede into the background, sometimes working to pass the president’s agenda but mostly serving as a venue for commentary on his performance. When it is not in the hands of the president’s party, Congress becomes a focal point for opposition, but still not for legislation.

In his first 100 days, Donald Trump signed only five bills into law—fewer than any other modern president. In a period rife with constitutional conflict in Washington, the first branch has done essentially nothing.

This willful passivity renders the rest of what happens in our government largely symbolic. The president can’t actually advance much durable, substantive policy change in the absence of congressional action. The ostentatious parades of executive orders that now mark the beginning of every new presidency are just attempts to cover up that frustrating reality. As Republican deficit hawks have learned in recent months, DOGE can only talk about spending cuts: If Congress doesn’t act, the budget doesn’t change.

The same is true of regulatory reform. President Trump is testing the boundaries of his power to rein in the independent agencies that Republicans have complained about for years, but it is far from clear if much of what he is doing will endure. Congress could achieve such change well within the boundaries of its undisputed powers. It just hasn’t moved to do it. The judiciary has been trying to press this point for years. The Supreme Court’s administrative-law decisions over the past half decade have all sought to create space for Congress to reassert itself against regulatory agencies. But all the Court can do is create opportunities for such reassertion; it can’t make Congress act.

Read: Why isn’t congress doing anything?

The policy terrain of the Trump era is also rife with opportunities for legislative action, if only Congress would seize them. Trump has made tariffs an organizing principle of his economic policies, for instance, and in ways that many congressional Republicans disapprove of. Tariff policy plainly belongs to Congress—the Constitution could not be clearer about that. Legislators have delegated broad emergency powers to the president to set tariff rates, but could withdraw that delegation, or refashion it as they choose, anytime they want. If members are unhappy about Trump’s tariffs (as large majorities in both houses appear to be), they can do something about them, but Republican leaders have chosen not to. House Republicans even changed the rules of their chamber so that they couldn’t vote on a repeal of Trump’s tariff authorities—robbing themselves of power rather than using it.

Some of the president’s advisers are eager to push Congress even further aside in the coming years and insist on the executive’s power to “impound” federal money—that is, to decline to spend funds appropriated by Congress that the president would rather not spend. This is an affront to the legislature’s most fundamental power. The administration is basically challenging Congress to a duel that the legislative branch cannot decline without surrendering its honor.

But surrendering its honor, and its power and ambition, is precisely what Congress has been doing for two decades. As long as Congress won’t do its job, the other branches will keep overreaching—making it harder for them to do their proper jobs as well, and leaving the country’s most significant challenges unresolved.

Our Constitution created a republican form of government, and Madison was right to insist that, in such a government, the legislative power necessarily predominates. As long as Congress declines to at least try to predominate, though, our system will not work as intended.

And Congress has only itself to blame. It has grown weak because its weakness is what its members want. There is no shortage of ideas for how to fix what now ails the institution. But all of them share one flaw: They will succeed only if legislators choose to pursue them. Congress cannot regain its strength until its members want it to.

So for all that we will rightly worry about presidential power in the next few years, we cannot break out of our constitutional bind without looking down Pennsylvania Avenue to the Capitol. Anyone contemplating where to seek change or how to direct reformist energies should take notice of a counterintuitive yet inescapable fact: Addressing the overreach of the judicial or executive branches requires first changing what members of Congress want.