President Trump is used to being a king.

For decades, his word was the final word in his domain. His advisers, princes and princess might offer their insights, but the decision of what would happen in the Trump Organization was his alone, if he chose to weigh in. No board of directors, no stockholders, just Donald Trump, unchecked.

On the campaign trail, it seemed pretty clear that he assumed that the presidency worked the same way. “Nobody knows the system better than me, which is why I alone can fix it,” he said during his speech at the Republican convention in July, a marked break from the traditional appeal to getting Congress to unite behind an agenda. He repeatedly dismissed endemic problems as being easy — and, if he had the authority of a chief executive, of a king, perhaps they would have been.

Unfortunately for Trump’s ambitions, that’s not how the American government works. On Friday morning, we got another reminder of Trump’s fundamental misunderstanding of the limited and constrained power of the chief executive of the United States — the latest in a long series.

Politico reported that the administration had issued a blanket ban on oversight requests sent by Democratic lawmakers. In other words, if Rep. John Smith (D-Somewhere) from the House Intelligence Committee wants the Department of Justice to provide information on an FBI investigation, the department has been informed not to respond to the request. A spokesman for the administration told Politico that departments were told “to accommodate the requests of chairmen, regardless of their political party,” which is a neat trick since the chairmen of committees of a Republican-controlled Congress are all Republicans.

This is the oversight that comes with the job of being president, one of the more nuanced aspects of the checks-and-balances system that was central to the Founding Fathers’ construction of the United States. The point of the Constitution, after all, was to prevent a president who could act with the impunity of a king, not to allow the presidency to be used in that way.

This is only one example of Trump’s bristling at the formal and informal checks that exist on his power. Others include:

Investigations. Trump has repeatedly railed against the investigations into his campaign and the behavior of his administration being run by congressional committees and the FBI. He has dismissed investigations into Russian meddling as being a “total hoax” and told NBC’s Lester Holt that the Russia investigation at the FBI was one reason he decided to fire FBI Director James B. Comey.

Information. The administration’s block on requests from Democratic members of Congress is only one way in which the White House hopes to prevent unhelpful information from getting out. Last month, The Washington Post reported that the administration had “removed or tucked away a wide variety of information that until recently was provided to the public, limiting access, for instance, to disclosures about workplace violations, energy efficiency and animal-welfare abuses.”

The judiciary. The judicial check on the chief executive’s power is explicit in the Constitution, and the judiciary’s willingness to weigh in on things Trump wants to do has earned it the repeated ire of the president.

He’s complained about judicial blocks on his immigration ban…

…called one judge a “so-called” judge…

…and complained about an entire circuit court.

The filibuster. Senate rules allowing a member to block legislation indefinitely through the use of a filibuster have unquestionably been abused in recent years to allow for a sort of casual filibuster that forces 60-vote cloture requirements on most pieces of significant legislation. Trump, frustrated by the need to cobble together policies that can earn that 60-vote margin, has repeatedly argued that the Senate should simply unilaterally eliminate the filibuster and adopt a 51-percent margin to pass any legislation.

Approval of his Cabinet. That frustration was evident during the early days of Trump’s administration when he was hoping to have his Cabinet approved. He repeatedly complained that Democrats were holding up his nominees, which, of course, is the constitutional prerogative of the Senate. (He also accused the Democrats of blocking his full Cabinet before he’d formally nominated a full Cabinet.)

Ultimately, the Republican Senate majority changed filibuster rules to approve several of Trump’s Cabinet picks without needing to gain any support from the minority.

Executive orders. Despite years of pejorative Republican rhetoric about the use of executive orders by President Barack Obama, Trump seized on the tool during his first weeks in office as a way of demonstrating a willingness to take action without waiting for Congress to pass legislation. The boundaries of those executive actions were often constrained specifically because Trump’s powers were limited, but, on occasion, he pushed those boundaries. He did so most notably in the case of his immigration ban, with the result we already have addressed above.

The media. While not stipulated in the Constitution, the media’s free-ranging role in questioning and challenging elected officials is a clear and historically validated check on power. Few things frustrate Trump as viscerally and frequently as reporting that positions Trump’s policies or actions in a negative light.

Most famously:

But other examples are legion.

Those are the words of a king who is being challenged by a peasant. In the old days, high in his castle on Fifth Avenue in Manhattan, such insolence could be waved away.

Now, as a president bound by rules, law and custom, his authority is not so sweeping and the opposition more robust — even as he scrambles to constrain it.