In seeking to influence the executive branch, the president is not without help. He relies on what the political scientist John Hart called the “presidential branch” — which consists of almost 2,000 staff members, several hundred under the White House proper and the rest in a variety of management organizations (National Security Council, Council of Economic Advisers, Office of Management and Budget) within the Executive Office of the President.

The advisers in the Executive Office and White House offer the president unbiased information and advice that serve his agenda. At least in theory. In practice, they pose a particular danger to a weak president. The political scientist Jonathan Bernstein has detailed how executive governance suffers in the absence of presidential leadership and can empower rogue policy entrepreneurship. As examples, he points to the policy debacles of Iraq under George W. Bush and the Iran-contra scandal under Ronald Reagan.

The Executive Office advisers not only have discretion over the information the president receives but also have opportunities to derail presidential proposals before they can even see the light of day.

Effectively managing the White House has been a challenge for all modern presidents. One prerequisite is an ability to articulate a policy vision and persuade senior advisers to develop and carry it out. Mr. Trump’s visible lack of control over the White House is in part rooted in his lack of firm policy beliefs — about immigration, gun control or foreign policy. Chaos is rampant in the Trump White House largely because the president is weak and easily manipulated by those who have access.

A mismanaged White House, a poor professional reputation and a weak presidency are not impossible to fix. Like Mr. Trump, other first-year presidents have had trouble adapting to the power dynamics of the White House and the Washington community. While some never recovered from disastrous starts (Jimmy Carter), others found their footing and became widely influential over the executive agencies (Bill Clinton).

Unfortunately, the current state of the White House already reflects the most obvious fix Mr. Trump could make: bringing in a more empowered and competent chief of staff. By most accounts, John Kelly had succeeded in improving the information flow, removing some of the key factional actors and reducing the leaks. A more experienced White House hand could probably do better, but at this point it isn’t clear Mr. Trump could attract that sort of A-list talent.