I'm a departmentalist, not a judicial supremacist.

Departmentalism holds that each branch of government has an equal authority to construe the meaning of the Constitution for itself when carrying out its own duties and responsibilities. The primary alternative, frequently asserted by the Supreme Court, is that the judicial branch has the ultimate and preeminent authority to interpret the Constitution.

Departmentalism was first and most elaborated articulated by the Jeffersonians. Confronted by a federal judiciary that enthusiastically supported the Federalist Party's Sedition Act of 1798, which was used to shut down Jeffersonian newspapers in the run-up to the 1800 election, the Jeffersonians looked for vehicles for explaining why the Sedition Act was unconstitutional and in violation of both enumerated powers and the First Amendment.

The Federalists, of course, thought the Sedition Act was constitutional on the merits. They also thought that the federal courts were the only institution entitled to evaluate the constitutionality of federal statutes. They sometimes even suggested that the Constitution was just whatever the courts said it was.

Jefferson thought it "a very dangerous doctrine indeed" to "consider judges as the ultimate arbiters of all constitutional questions."

The Constitution has erected no such single tribunal, knowing that to whatever hands confided, with the corruptions of time and party, its members would become despots. It has more wisely made all the departments co-equal and co-sovereign within themselves. . . . I know no safe depository of the ultimate powers of the society but the people themselves; and if we think them not enlightened enough to exercise their control with a wholesome discretion, the remedy is not to take it from them, but to inform their discretion by education. This is the true corrective of abuses of constitutional power.

Departmentalism has rarely held sway in American politics, and it has become weaker over time. Elected politicians have found plenty of reasons to pass the buck to the courts whenever possible. Sometimes it seems that they barely know how to meet their own constitutional responsibilities at all. Democrats in Congress today certainly seem uncertain about how best to understand or defend congressional authority under the Constitution.

Congress and the president frequently disagree about the scope of their respective institutional authority. Those disagreements can sometimes be intense, and each branch has its own set of political tools to advance its constitutional understanding and attempt to effectuate it. Presidents have sometimes asserted that Congress has encroached on their own exclusive constitutional domain, and legislators have sometimes resisted those claims. Presidents have sometimes claimed that Congress has abused its own constitutional powers or that Congress has interfered with the president's ability to perform his own constitutional functions. They have ways to act on those claims, and Congress has ways to push back.

I first became interested in studying the impeachment power because it was a constitutional domain in which courts had little sway. Congress construed its own authority to exercise the impeachment power, and Congress sometimes used the impeachment power as an instrument for advancing its constitutional understandings about the rules, norms and practices that would govern the American political system.

There are those who would prefer to judicialize all constitutional disputes. They would invite judges in to resolve not merely matters of individual right under the terms of the Constitution but also matters of interbranch relations. Matters that might be managed through political negotiation, compromise, norms and comity might instead by managed by reference to legal rules articulated by judges. The result might be tidier but it will be less flexible, probably less functional, and ultimately less democratic.

The impeachment power, like any other constitutional power, can be abused. The Senate sits in judgment of whether the House has misused its sole power to impeach federal officers. The people sit in judgment of whether the House and the Senate together have properly wielded this most formidable constitutional weapon. I know no safe depository of the ultimate powers of the society but the people themselves