Economy

The perception of a less independent central bank could lead to greater uncertainty in expectations of monetary policy, or expectations of higher inflation, and that would translate into higher long-term interest rates.

Mr. Trump has agitated for the Federal Reserve to lower short-term interest rates to reduce the government’s borrowing costs, part of a broad attack on the central bank’s independence.

The risk is that investors begin to doubt that the United States will pay back its debts and start demanding higher interest rates, stunting borrowing across the economy.

Larger debts and higher interest rates also increase spending, forcing the government to borrow even more.

The United States already spends more financing its debt than it does on defense.

Mr. Trump’s crackdown on immigration is also putting pressure on America’s fiscal situation, the C.B.O. said.

If the tariffs survive the legal challenge or Mr. Trump replaces them with different levies, a future president could, with a stroke of the pen, immediately slash the remaining import taxes.

The budget office expects the American population to have 5.3 million fewer people in 2035 than it previously expected, reducing projected tax revenue, with an overall budget hit of roughly $500 billion over that time frame.

The Supreme Court could soon throw many of them out.

When they passed the tax cuts, Republicans took the unprecedented procedural step of locking many of them in permanently, meaning the cuts would require another act of Congress to reverse them, an unlikely event.

That law, which provided its biggest benefits to the rich as it also cut spending on programs for the poor, came in at a total cost of roughly $4.7 trillion over the next nine years, the C.B.O. said.

Our budget projections continue to indicate that the fiscal trajectory is not sustainable.

The amount of debt held by the public is expected to become much larger than the annual output of the economy, reaching 120 percent of gross domestic product in 2036.

That would surpass levels reached in the aftermath of World War II and put the world’s most important economy at risk of a destabilizing debt crisis.

The most expensive policy change made so far by Republicans and Mr. Trump has been the broad income tax cuts they passed last year.

The effect of these dramatic changes has nearly been a wash when it comes to the overall federal budget.

Those were the findings of the Congressional Budget Office, the nonpartisan scorekeeper, in its annual benchmark forecast for the federal budget released on Wednesday.

The situation, on paper at least, has gotten only somewhat worse, but not significantly, under Mr. Trump’s unorthodox policy mix.

The country is still on track to borrow what economists consider an alarming amount of money in the coming years.

Officials said the money is being held in a Qatari account.