In reality, however, this independent congressional power depends a great deal on its willingness to uphold its institutional responsibility, to see itself as a separate branch of government that is jealous of its own power and prerogatives. The constitutional theory isn’t that, say, Democrats will check Republicans but that Congress will check the presidency.

Substitute an overriding partisan purpose for institutional responsibility, and the system starts to falter. We see this most plainly in the impeachment context. Congress has quite clearly tended to view impeachment primarily through a partisan lens. When Mitt Romney voted to convict Donald Trump during Trump’s first impeachment trial in 2019, he was the first senator in American history to cross partisan lines to vote to convict a president.

Congress is now less an independent branch of government and much more a collection of partisan foot soldiers supporting or opposing the sitting president’s agenda. Combine this partisan purpose with a closely divided country and you have a formula for deadlock, and worse.

Politics abhors a power vacuum, and Congress’s absence has been filled by the presidency. As Congress shrinks, the presidency grows. On a bipartisan basis, presidents now choose to act whenever Congress “fails.”