By William Ford and William Hoagland

   His administration would do this at a massive scale, targeting “large chunks” of federal agencies’ budgets.

   All of this would happen in defiance of federal law -namely the Impoundment Control Act. Passed in 1974, the law requires the president to comply with appropriations laws and spend federal funds, unless he gets approval from Congress to do otherwise.

   In Trump’s view, the Impoundment Control Act poses no threat to his plans, because he believes the president possesses an inherent constitutional power to refuse to spend, or “impound,” appropriated funds.

   Although the Constitution nowhere mentions a “power to impound,” Trump’s allies have in recent weeks defended this view as deeply rooted in American history and tradition. They argue that the Impoundment Control Act unconstitutionally infringes on the president’s alleged inherent impoundment power. And they cast impoundments as an innocuous tool to save taxpayer money.

   On each point, Trump and his advisers are wrong. Neither American history and tradition nor the text and structure of the Constitution support the notion of an inherent presidential impoundment power on which the Impoundment Control Act encroaches.

   Although Trump and his allies are right that presidents going back to the founding have at times spent less money than Congress has appropriated for a given purpose, they are wrong to suggest that this supports the notion of an inherent presidential power to impound.

   First, in many instances, presidents have been able to spend less than the full amount appropriated because Congress gave them this discretion in statute. Such was the case when President Thomas Jefferson impounded funds for gunboats in 1803. Congress had authorized Jefferson to spend “a sum not exceeding fifty thousand dollars” on a “number not exceeding fifteen gun boats.”

   Almost 150 years later, when President Harry S. Truman impounded funds for federal programs deemed not to advance the Korean War effort, it was because Congress gave him that discretion in sections 1211 and 1214 of a 1950 omnibus appropriations law.

   Only three presidents appear to have explicitly claimed an independent constitutional power to impound funds. Truman seems to have done so at a 1950 press conference, where he noted that if the president “doesn’t feel like money should be spent, I don’t think he can be forced to spend it.”

   President John F. Kennedy appears to have done the same in a 1962 letter to Congress. And President Richard Nixon did so repeatedly -both in court and through congressional testimony.

   Each of these presidents governed in the last 80 years. The idea of an inherent power to impound is thus not deeply rooted in American history but rather recent, and quite infrequently invoked at that.

   Indeed, it appears that it was not until the Nixon administration that any president pressed this argument in court. When Nixon did, he resoundingly lost in federal courts in Louisiana and D.C.

   These cases reflect only a small slice of the numerous lawsuits filed against the Nixon administration for impounding billions of dollars in funds for public housing, drug rehabilitation, disaster relief, urban development, rural environmental assistance and other programs.

   In 1973 alone, Nixon impounded $18 billion in authorized and appropriated spending, representing 34 percent of all discretionary domestic spending that year.

   For the coming fiscal year, for which nondefense discretionary spending is capped at $711 billion, withholding the same percentage of funds would result to more than $240 billion in impoundments.

   Nixon impounded funds at this scale not to save taxpayers money but to nullify the will of Congress and defund programs he disagreed with on policy grounds. And he claimed unbounded constitutional power to do this in order to put himself above the laws he sought to flout.

   This is why Congress passed the Impoundment Control Act in 1974 -to definitively outlaw this practice. And it is why federal courts ruled against Nixon -because the idea of a presidential power to impound cannot be reconciled with the text and structure of the Constitution, which creates co-equal branches of government and divides power among them, so none reigns supreme.

   When it comes to federal spending, the Constitution gives Congress the power of the purse, not the president. To claim that the president has an inherent impoundment power is to place the president outside of and above the system of checks and balances that the Constitution’s framers so carefully designed.

   This is exactly what Trump seeks to do now in claiming an inherent power to impound -not to pursue cost savings for the American people, but seize for himself the authority to do whatever he wishes as president and brush aside checks on his power.

   Trump previewed this approach to impoundments in 2019 when he placed an unlawful hold on American security assistance to Ukraine in an effort to coerce Ukrainian President Volodymir Zelensky into investigating his likely opponent in the 2020 presidential race, then-former Vice President Joe Biden.

   Last time, Trump backed down and released US assistance to Ukraine. This time, he’s saying he would not have to -indeed, that he has had the power all along to spend or not spend appropriations as he sees fit. Neither American history and tradition nor the Constitution’s text and structure provide support for this vision of governance.