Hospitals understandably dislike these proposals, and there may well be a better dividing line. It’s also possible that in some cases, the federal government should pay higher fees to private practices rather than pay lower fees to hospital affiliates. The administration’s budget contains only a thumbnail sketch of its own ideas, and the details clearly matter.

But Democrats are not debating the details. Instead, a proposal to improve the efficiency of health care spending is being treated as an attack on the availability of health care.

This is not a new phenomenon, of course. The Affordable Care Act included substantial reductions in Medicare spending. Those cuts, like Mr. Trump’s proposals, came mostly at the expense of providers rather than patients. But Republicans chose to attack the changes in language strikingly similar to the language Democrats have used in recent weeks.

Both parties have fallen into the unfortunate habit of characterizing every proposal to reduce Medicare spending as an attack on the program’s beneficiaries. In fact, careful stewardship of spending is necessary to ensure the program can help as many people as possible.

Mr. Trump is guilty of contradicting his campaign promise that he would not seek to cut Medicare spending. But it is the promise that was irresponsible, not the budget proposal.

Some items on Mr. Trump’s list of proposed savings have obvious downsides. For example, he has proposed to cut federal spending by increasing the annual amount that several hundred thousand Medicare beneficiaries are required to pay for needed medications. The budget also proposes large cuts in Medicaid that would reduce the availability of health care for many lower-income and disabled Americans.

But a president’s budget is just a list of ideas. It's up to Congress to pick the good ones.

Support for past cuts in Medicare spending was driven in part by concerns about the growth of the federal debt. Both parties lately have taken a more relaxed view of the government’s borrowing capacity, in part because apocalyptic predictions about the current level of federal debt look rather silly in retrospect. But the government’s ability to borrow money is not a justification for the wasteful spending of tax dollars.