Arizona Senator John McCain has received a fair bit of attention for calling his colleague, Kentucky’s Rand Paul, a “wacko bird” because of Paul’s concerns about the possible use of drones to attack American citizens on American soil. But another McCain quote, uttered in the same context, deserves far more attention. In attacking Paul’s thirteen-hour filibuster aimed at calling attention to the issue, McCain said:

We’ve done, I think, a disservice to a lot of Americans by making them think that somehow they’re in danger from their government. They’re not. But we are in danger from a dedicated, longstanding, easily replaceable-leadership enemy that is hell-bent on our destruction.

This is a remarkable statement from a United States senator, still more remarkable from a Republican, and even more so from someone who sometimes accepts the label of conservative. The reality, embraced by most Republicans and nearly all American conservatives, is that the people of any polity are always and forever in danger from their government.

If the senator sat down with a book or two about the Constitutional Convention in Philadelphia in the summer of 1787, he would see that the ubiquitous danger of arbitrary governmental action was at heart of those discussions and the effort to craft a system that protected the people from that danger. The chief agency for doing so was an elaborate system of checks and balances that included the ability of congressional members to raise the alarm about executive power in order to check the executive branch from trampling on the rights of citizens.

Alexander Hamilton, who like McCain saw little danger from executive power, wanted presidents to be elected for life and to wield an absolute veto power over legislation, meaning he could negate any bill passed by Congress with complete immunity from any legislative response.

But Connecticut’s Roger Sherman had another idea, at the other end of the spectrum. He wanted the president to be “nothing more than an institution for carrying the will of the legislature into effect . . . the person or persons ought to be appointed by and accountable to the legislature only, which [is] the depository of the supreme will of the society.” In other words, the executive would have no independent power, lest he combine it with some new technological wonder as yet inconceivable (such as drone aircraft, perhaps) to threaten the lives and safety of citizens.

Like Hamilton’s radical idea, Sherman’s unbalanced concept was rejected by the delegates. But the ultimate outcome was born of two interlocking and competing imperatives that troubled the Founders—the need to curtail the whims and abuses of executive power; and the need to employ executive power to limit the whims and abuses of legislative power. Although the abuses of England’s King George III had instilled in the American consciousness a profound distrust of executive power, later experiences had taught them that unchecked legislative power could be equally dangerous. After the Revolution, most of the new states, following the lessons of the Revolution, had crafted governmental systems with feeble executives and potent legislatures. The result over the years had been a growing catalogue of legislative abuse.

“One great object of the Executive,” declared Pennsylvania’s Gouverneur Morris, an eloquent and blunt aristocrat, is to control the Legislature.” That’s why he wanted the new president to be selected by the people in a way that would give him an independent power base. But the president would not be sovereign. “The Magistrate is not the King,” said Morris, “but the prime-minister; the people are the King.”

Morris was instrumental in guiding the convention to a view of a government in which the legislative and executive branches would be co-equal and competitive. That’s how we got the Electoral College, the four-year presidential term and the U.S. president as the only person in government who can claim to speak for all the people. But big work remained for the delegates as they sought to craft a system in which powers would be shared intricately by the independent branches.

Thus can the president select his top ministers, but only with the “advice and consent” of the Senate. Judges are nominated by the president but confirmed by the Senate. Congress controls impeachment not only of executive officials but also judges. The president negotiates treaties, but they remain lifeless until ratified by a two-thirds Senate vote. The president commands the country’s armed forces, but only Congress can declare war. Congress passes legislation, but the president can veto it—and a two-thirds vote of Congress can overturn that veto.

But of course you know all this. And you know that each branch of government, under this system is charged with protecting its institutional prerogatives and also using its institutional powers to protect citizen’s rights from abuses of the other branches. Warning about possible abuses is an integral part of this institutional responsibility.

That’s what Rand Paul was doing when he initiated his thirteen-hour filibuster the other week, and most of official Washington, recognizing the underlying seriousness of his message and rectitude of his approach, offered a measure of praise for his efforts.

But not John McCain. By ridiculing his colleague and suggesting Paul acted irresponsibly in warning about possible governmental abuse, McCain demonstrated that he had somehow lost sight of the fundamental philosophical underpinning of the American system.

Even more striking was a Wall Street Journal editorial that twitted Paul for questioning whether the president can kill Americans, on U.S. soil or overseas, without due process if he believes, unilaterally, that those Americans could pose a danger to others. “He’s apparently serious,” said the Journal of Paul, “but his argument isn’t.” The Journal said the president has an unchecked right to kill Americans designated—by the president—as an enemy combatant.

This kind of thinking—and the policies it could spawn—deserves plenty of debate and discussion. Congress has a big role to play in such debates and discussions. Rand Paul stepped up to that debate in a measured and responsible way. He deserves plaudits, not derision, for using the Constitution to defend the Constitution—and for warning of the ever-present dangers posed to citizens everywhere by their governments. The Founding Fathers would understand, even if John McCain misses the point.

Robert W. Merry is editor of The National Interest and the author of books on American history and foreign policy. His most recent book is Where They Stand: The American Presidents in the Eyes of Voters and Historians.