The Trump administration asked the Court to bless firing qualified soldiers because they are transgender. Solicitor General John D. Sauer filed the petition Friday, asking the nine justices to overturn a June ruling by the federal appeals court in Washington that found the Pentagon’s ban on transgender service members was “both arbitrary and based upon animus.” That word — animus — is the one the administration cannot escape. It is a finding made on a developed record, after a hearing, by a court applying the equal-protection principle that binds the federal government through the Fifth Amendment’s Due Process Clause. It is not editorial commentary. It is the law’s diagnosis.

And so the administration is asking the Supreme Court to do what the appeals court refused to do: pretend the diagnosis isn’t there.

The deference argument the petition makes is real, and it deserves its strongest form before the audit begins. The Constitution gives the political branches substantial authority over military composition. Article I, §8 grants Congress the power “To raise and support Armies” and “To make Rules for the Government and Regulation of the land and naval Forces.” Article II, §2 makes the President the “Commander in Chief of the Army and Navy.” The Supreme Court has long recognized a military-judgment deference doctrine — most prominently in Rostker v. Goldberg, 453 U.S. 57 (1981), upholding male-only registration for the Selective Service — that gives the political branches wide latitude in personnel decisions where military effectiveness is at stake. The executive’s authority to set enlistment standards, structure the ranks, and assign duties is, in the ordinary case, entitled to substantial judicial respect.

That is the deference the administration is invoking. It is the right deference, on the right subject, and it is doctrinally sound.

But deference is not a license to discriminate. Equal protection operates as a structural constraint on every exercise of government power, including the military authority the administration invokes. The Fourteenth Amendment’s Equal Protection Clause binds the states; against the federal government, the same principle runs through the Fifth Amendment’s Due Process Clause — a doctrine the Court announced in Bolling v. Sharpe, 347 U.S. 497 (1954), and has reaffirmed in successive decisions.

Under that principle, the Court has held repeatedly that classifications drawn for the purpose of disadvantaging a politically unpopular group fail even the most deferential rational-basis review. Some objectives are not legitimate state interests. Animus can never be one. That is the holding of Romer v. Evans, 517 U.S. 620 (1996), in which the Court struck down a state constitutional amendment whose only purpose was to harm gay men and lesbians.

The principle reaches federal action as well. In United States v. Windsor, 570 U.S. 744 (2013), the Court struck down the federal definition of marriage on the same equal-protection logic running through the Fifth Amendment. That is the doctrinal machinery the D.C. Circuit panel applied.

Judge Robert Wilkins, writing for the panel, found that the ban on transgender service members “appears driven by the bare desire to harm a politically unpopular group.” That is an equal-protection finding on a developed record. It is the kind of finding the Supreme Court has never reversed when the lower court has done the work — because animus-based classifications are categorically outside the zone in which deference operates. Even Rostker, the high-water mark for military deference, expressly relied on the absence of any showing that the policy was driven by stereotype or animus. When the animus is found, deference runs out.

Read the executive order the administration is defending and the diagnosis sharpens. The order declares that transgender troops’ health needs are “inconsistent” with military service — a sweeping claim about a population of qualified service members the Pentagon cannot defend on the merits. The order’s defenders have fallen back on appeals to “readiness” and “unit cohesion” rather than anything resembling evidence. As the administration’s own attorneys conceded below, the affected service members are qualified individuals meeting every military standard. There is no medical disqualification. There is no readiness failure. There is a category of person the executive has decided to remove.

The plaintiffs — the National Center for LGBTQ Rights and GLAD Law — sued in February. They won in June. They should win again when the Supreme Court returns from summer recess in October to consider whether to take the case. Jennifer Levi, GLAD Law’s senior director of transgender and queer rights, put the point plainly: “There is no reason to waste millions of taxpayer dollars to kick out thousands of highly trained, skilled, and decorated troops based on nothing but hostility and this administration’s political whims.” That is the position the justices will weigh against the solicitor general’s call for deference. It is the position the Equal Protection Clause, in either of its constitutional homes, was written to protect.

The legal ground has been shifting under the administration’s feet for months. In June, the D.C. Circuit blocked the expulsion of transgender troops before this latest round began; in July, a federal judge ordered the Pentagon to compare its testosterone policies for trans and cisgender service members — a routine inquiry that would be unnecessary if the medical premise of the executive order were sound. Each new filing tightens the legal noose, and each new filing is followed by an appeal.

Sauer can ask the Court to reverse the finding of animus. He cannot ask it to erase the finding from the record. The record contains the panel’s equal-protection ruling. The record contains the administration’s concession that the affected service members meet every standard. The record contains an executive order whose own language admits that its premise is policy preference, not military judgment. By the time the Court returns on Oct. 5, the administration will have spent the better part of a year asking every available forum to ratify a decision the Constitution does not authorize.