Saddled with nominal control of the Senate but a vanishingly narrow working majority, Democrats have, of late, taken to venting their frustrations on the filibuster. It is not that the country is basically split down the middle, and has been for the better part of four decades. It is that their party is the natural governing majority, but the ancient institutions of our government keep them from realizing the will of the people. The filibuster, by requiring a majority of three-fifths of the Senate to end debate before a final vote, must therefore be eliminated. That way, the Senate can function properly, the government can represent the people, and democracy can be salvaged. Cloaked in claims of “increasing democracy,” who could object? But dig a little deeper, and one finds that in their attacks on the filibuster, the Democrats are, in truth, pulling upon a thread that, if tugged too tightly, could unravel the entire Senate, and therefore the balance of the deliberately constructed system of government. The Senate runs according to a series of precedents, traditions, and, above all, the 44 “standing” rules of the chamber (differentiating them from the House rules, which expire at the end of every Congress). The apparent purpose of the rules is to manage business within the Senate, but they often read like a bill of senatorial rights, stopping the rest of the body from infringing on the prerogatives...