President Obama has to be discouraged.

On Monday, the Supreme Court heard oral arguments in U.S. v. Texas, the case that will determine the fate of his executive order on immigration. Sometimes inferences drawn from oral arguments can be misleading, and this is what Obama and his supporters have to hope for: If the arguments were any indication, we're looking at a 4-4 tie. And if this happens, the lower court ruling that the order is unconstitutional will stand.

The latest legal challenge to the Obama administration concerns its Deferred Action to Parents of Americans and Lawful Permanent Residents (DAPA) order. The basic idea of the order is that because Congress has appropriated only a small fraction of the resources that would be necessary to deport everyone who is in the country illegally, the administration has to prioritize. Obama's order simply makes explicit the informal decision over who to report (criminals rather than law-abiding people with children who are citizens, for example) and allows undocumented immigrants who are not going to be subject to deportation anyway a measure of security and the ability to work legally.

The case for the constitutionality of DAPA is straightforward. Determining how to apply the law given scarce resources is a core executive power. There is ample precedent for Obama's actions, and the fact that Congress would not make the same policy choices is irrelevant unless they can pass legislation ordering Obama to do things differently (and give him the resources to make it possible.)

So the arguments in favor of DAPA are strong, but in terms of whether the orders will stand up legally they're only as strong as the Supreme Court says they are. Here, the news from Monday's argument was far from encouraging.

The three members of the Court's conservative faction who spoke at oral argument — Chief Justice Roberts and Justices Kennedy and Alito — seemed to support Texas' opinion, suggesting that if DAPA was upheld then there would be a slippery slope allowing the executive branch to refuse to deport anyone. "What we're doing is defining the limits of discretion," Justice Kennedy told U.S. Solicitor General Donald Verrilli. "And it seems to me that this is a legislative, not an executive, act." The conservative justices were also agitated by the temporary "lawful" status the government's memo granted to undocumented immigrants who will not be deported.

For his part, Texas Solicitor General Scott Keller also got a rough ride from the Court's liberal faction. Justice Kagan focused in particular on Keller's concession that it was not illegal for the executive branch to defer action on the groups covered by DAPA. "You're saying that the government could do this case-by-case, one-by-one with respect to all the people in the class," asked Kagan incredulously, "but that the government cannot identify the entire class and say we're forbearing from enforcement?" As for the "lawful presence" language that obsessed both the state of Texas' briefs and the conservative justices, Kagan correctly observed "that phrase really has no legal consequence whatsoever."

Kagan's performance was masterful — but it's unlikely that it will be enough to save DAPA. As weak as Texas' arguments were, they seemed good enough to get them the tie they're looking for.

Some Court observers had speculated before oral arguments that Chief Justice John Roberts might try to avoid a 4-4 split by agreeing with the Court's liberal faction that Texas lacked the legal standing to challenge DAPA. This is still possible. On Monday, however, he seemed skeptical, asking Verrilli to begin with the standing argument and then peppering with questions suggesting that he believed that Texas had the standing to sue.

An evenly split court affirming the 5th Circuit's opinion striking down the order would not legally settle the issue of the executive branch's authority. But it will mean that a class of undocumented immigrants will remain in an unnecessary state of legal limbo. And it also means that the policy will ultimately be determined by the next president: not only through the immigration policy he or she favors, but on who (and whether) he or she will be able to appoint to the Supreme Court.