On Wednesday night, Chief Justice John Roberts temporarily halted a lower court order, which would have required the Trump administration to make approximately $2 billion in foreign aid payments that it had stopped as part of a broader attack on the US Agency for International Development (USAID).Its important not to read too much significance into Robertss temporary order in this case, known as Department of State v. AIDS Vaccine Advocacy Coalition. Judges often have the power to hit pause on a case while they take more time to figure out how the law requires them to act indeed, many of the lower court judges whove halted Trump administration policies relied on similar authority when they did so. Its likely that Roberts issued Wednesdays order to give himself and his colleagues more time to consider the questions presented by the AIDS Vaccine case.But the current dispute before the Supreme Court is significant for at least two reasons. The first: it is the first Trump-era case involving impoundment, a legally dubious claim that the president may cancel federal spending that is mandated by laws enacted by Congress. The Impoundment Control Act of 1974 places very strict limits on the presidents ability to second-guess Congresss spending decisions typically the president must seek permission from Congress before canceling spending. But Trump has nonetheless claimed the power to do so without legislative approval.The second reason is that, in a document Trumps Justice Department recently filed in the Supreme Court, Trumps legal team seems to reveal how they plan to get around the Impoundment Control Act and similar rules requiring the president to obey federal spending laws.Significantly, the Trump administration does not argue at least not yet that the president has the inherent constitutional authority to impound funds. Indeed, the DOJs recent filing does not even argue that Trumps decision to halt USAID spending is legal. Instead, the Trump administration suggests that federal courts lack the authority to issue broad orders reinstating whole swaths of government spending canceled by the administration, and that these cases must instead be resolved on a piecemeal basis.Think of it this way: Suppose that the Trump administration issues an illegal order forbidding the government to pay any contractor named Susan. Now suppose that 10,000 Susans who are owed money by the federal government seek a single court order declaring this anti-Susan policy illegal. The Trump administrations legal arguments suggest that such a court order is not allowed, and each Susan may need to bring their own individual legal proceeding to get paid.Needless to say, this tactic could significantly hinder efforts to make the Trump administration comply with federal spending laws. If the Supreme Court embraces the administrations arguments, Trump and his subordinates would remain free to issue blanket orders canceling entire categories of federal spending. Meanwhile, anyone impacted by these cancellations would potentially need to retain their own legal counsel, determine which court or federal agency has jurisdiction over their claim, and then bring a proceeding that could take months or years to resolve. Many of these potential litigants may simply give up. Others could go out of business while waiting for the government to pay what it owes.The president is not allowed to impound funds appropriated by CongressThe question of whether a president may simply refuse to spend money that Congress has ordered the executive branch to spend is very easy to resolve. As future Chief Justice William Rehnquist wrote in a 1969 Justice Department memo, it is in our view extremely difficult to formulate a constitutional theory to justify a refusal by the President to comply with a congressional directive to spend. Theres simply nothing in the Constitution which supports the claim that the president may impound funds. And there are several provisions of the Constitution that cut against this claim, including one which states that the president shall take care that the laws be faithfully executed. That provision imposes a duty on the president to faithfully execute any law calling for federal spending.At least two members of the Supreme Courts current Republican majority, moreover, have previously indicated that they agree with Rehnquists 1969 memo. As a White House attorney in 1985, Roberts wrote that it is clear that the president cannot impound funds in normal situations (though he did, in a potentially ominous sign for USAID, suggest that the presidents authority may be greater in cases involving foreign affairs). Roberts added that no area seems more clearly the province of Congress than the power of the purse.Similarly, Justice Brett Kavanaugh wrote in a 2013 opinion, when he was still a lower court judge, that even the President does not have unilateral authority to refuse to spend funds appropriated by Congress.Nevertheless, Trump signed sweeping executive orders seeking to halt federal spending. That includes a January 20 order purporting to impose a 90-day pause in United States foreign development assistance for assessment of programmatic efficiencies and consistency with United States foreign policy, as well as a domestic spending order so broad that it seemed to freeze Medicaid (although the White House backed off that policy somewhat after it triggered a bipartisan backlash). The AIDS Vaccine case offers this Supreme Court its first opportunity to weigh in on Trumps efforts to halt federal spending. The Justice Departments narrow arguments suggest that, at the very least, Trumps lawyers would prefer to delay a broader showdown over whether Trump can simply cancel any funding he wants.So whats the specific question before the Court in AIDS Vaccine?The specific dispute before the justices right now arises out of a pair of orders issued by federal District Judge Amir Ali. The first indicated that the Trump administrations blanket suspension of USAID funding was illegally arbitrary because the administration has not offered any explanation for why a blanket suspension of all congressionally appropriated foreign aidwas a rational precursor to reviewing programs for inefficiency or noncompliance with Trumps policy goals.Accordingly, Ali temporarily forbade the administration from suspending, pausing, or otherwise preventing the obligation or disbursement of appropriated foreign-assistance funds that had been authorized as of January 19.The second order sought to enforce the first one, by requiring the State Department and USAID to pay all invoices and letter of credit drawdown requests on all contracts for work completed prior to the entry of the Courts [first order] on February 13. The bulk of the Trump administrations brief to the justices, meanwhile, argues that Judge Ali lacks jurisdiction over this case, and that Alis orders were also too broad because they sought to reinstate payments that arent owed to the specific plaintiffs who brought the AIDS Vaccine case. Again, Alis second order requires the State Department to pay all invoices for work completed prior to a specific date, even if that work wasnt done by the AIDS Vaccine plaintiffs.At least some of these claims are plausible. The Justice Department, under both the Biden and Trump administrations, has long railed against nationwide injunctions lower court orders which suspend a federal policy on a nationwide basis, rather than issuing more narrowly tailored relief to individual plaintiffs. Some members of the Court, most notably Justice Neil Gorsuch, are passionate advocates of the view that broad, nationwide relief must be curtailed. (I have also argued that Gorsuchs stance against nationwide injunctions has significant merit.)But a Supreme Court decision preventing judges from issuing broad injunctions would also give the Trump administration considerable leeway to act illegally. Again, the administration would be free to issue broad new policies canceling funding that impacts millions of Americans. Then, even if the courts later determined that this new policy is illegal, the individuals and businesses who are owed money would have to bring their own proceedings demanding repayment.Some of this imbalance could be resolved through class actions lawsuits which allow multiple parties with similar legal claims to join together in the same proceeding. But there are also limits on who can bring such class actions, and its unclear whether multiple parties seeking to enforce multiple contracts with different terms would be able to show that their cases are sufficiently similar to permit a class action to move forward.All of which is a long way of saying that the courts are unlikely to fully constrain a president who is determined to cancel federal spending, even if he does so illegally. The executive branch is much more nimble than the judiciary, and this will be doubly true if the Supreme Court limits lower courts ability to block the Trump administrations policies on a nationwide basis.See More: