Attorney General Jeff Sessions announced on Thursday that the Trump administration will not defend the constitutionality of the Affordable Care Act’s guaranteed-issue and community-rating requirements, which prevent health insurers from discriminating against individuals with pre-existing medical conditions. Congressional Democrats have called the Trump administration’s move “a stunning attack on the rule of law.” Conservative commentators have responded that the Obama administration “set a precedent” for Thursday’s action by refusing to argue for the constitutionality of the Defense of Marriage Act in 2011. For hundreds of thousands of Americans who suffer from pre-existing medical conditions ranging from childhood diabetes to cancer, access to health care hangs in the balance. And not only does this debate have an enormous impact on the lives of ordinary Americans, but it also implicates some of our most fundamental constitutional norms.

One thing should be clear though: The “Obama did it too” defense does not fly. The Trump administration’s position on pre-existing conditions is legally indefensible—and the DOMA precedent provides no support for the Trump administration’s latest assault on the ACA. True, the Obama administration declined to defend a federal statute when it had strong reasons to believe the law was unconstitutional—and presidents all the way back to Thomas Jefferson have done the same. But Trump’s attack against the ACA is qualitatively different—and it is a much more serious threat to the constitutional allocation of powers between the executive branch and Congress.

Never before has the Justice Department declined to defend a federal statute when the arguments against the law are as threadbare as they are here.

Two points are essential toward understanding why the Obama administration’s DOMA decision does nothing to justify the Trump administration’s ACA stance. First, the Trump administration’s legal arguments against the ACA’s pre-existing-conditions protections are frivolous. Second, the Obama administration’s good-faith refusal to defend DOMA was not the first time that an administration declined to argue for the constitutionality of a federal law—and unlike the Trump case, the Obama administration had very good reasons to believe that DOMA was unconstitutional (reasons that the Supreme Court ultimately adopted in striking down the law). Blaming the Obama administration for the most recent Trump turnabout makes no more sense than blaming the Jefferson, Coolidge, Roosevelt, Truman, Kennedy, Johnson, Ford, Carter, Reagan, Bush I, Clinton, or Bush II administrations for their refusals to defend federal statutes that they thought suffered from serious constitutional flaws.

On the first point, the Trump administration’s argument boils down to the following: Congress would not have wanted the ACA’s protections for patients with pre-existing conditions to remain in place without the individual mandate, so now that Congress has gutted the individual mandate as part of the December tax law, the protections for patients with pre-existing conditions must fall too. The fatal flaw in that argument is glaring: Congress actually voted to gut the individual mandate while keeping the protections for patients with pre-existing conditions in place as part of that December tax law, which President Trump gleefully signed less than six months ago. There is no need to speculate on what Congress would have wanted when we know exactly how it voted within the past half year.

There is slightly more nuance to the Trump administration’s argument, but not much. For reasons of parliamentary procedure, Congress did not repeal the individual mandate outright in the December tax law—rather, it eliminated the penalties for not complying with the individual mandate after 2018. For present purposes, though, that is a distinction without a difference. Congress knew exactly what it was doing: It was rendering the individual mandate ineffective while maintaining the pre-existing-conditions protections. The Trump administration’s latest argument—that Congress wanted to do the thing it didn’t do when it had the chance six months ago—is a blatant attempt by the executive branch to wrest the lawmaking power from the House and Senate.

So what does all of this have to do with the Defense of Marriage Act? Well, not a lot. In the DOMA case, the Obama administration argued that the federal government is not allowed to discriminate against same-sex couples, an argument with which the high court eventually agreed. In the ACA case, the Trump administration is arguing that health insurers have a right to discriminate against patients battling chronic illnesses, an argument that is as illogical as it is cruel. The contrast could not be more stark.

But did the Obama administration’s refusal to defend DOMA set a precedent allowing the Justice Department to decline to defend a federal law that it considers to be unconstitutional? Certainly not. That precedent existed long, long before 2011.

In 1996 (incidentally, the same year that DOMA was enacted), the Clinton Justice Department sent a letter to Senate Judiciary Committee Chairman Orrin Hatch explaining why the administration was refusing to defend a newly enacted federal law that required the discharge of HIV-positive service members. The letter noted dozens of prior instances in which an administration had declined to defend a federal law in the lower courts or on appeal. Among others:

• The Coolidge administration declined to defend (on appeal) a statute that required Senate consent prior to the removal of postmasters.

• The administration of Franklin Roosevelt declined to defend (also on appeal) a statute that granted for-cause removal protection to Federal Trade Commission members.

• The Truman administration declined to defend a statute that prohibited the payment of salaries to three federal employees who were accused of being communists.

• The Kennedy and Johnson administrations declined to defend a statute that allowed federal funds to go to hospitals with “separate but equal” facilities for blacks and whites.

• The Ford administration declined to defend a statute governing the process for appointing members of the Federal Election Commission.

• The Carter administration declined to defend a statute that directed the Army to sell surplus firearms to members of the National Rifle Association, but not to nonmembers.

• The Reagan administration declined to defend a statute that allowed a single house of Congress to compel the deportation of certain non–U.S. citizens as well as a statute that allowed for the appointment of an independent counsel to investigate high-ranking federal officials.

• The first Bush administration declined to defend a statute that sought to ensure that minority-owned broadcast stations would receive preferences in Federal Communications Commission licensing.

The practice did not begin with Coolidge: President Jefferson’s administration declined to defend portions of the Judiciary Act of 1789 in the landmark case of Marbury v. Madison. And it did not peter out with Clinton: The second Bush administration likewise declined to defend (on appeal) a statute that required mass transit agencies—as a condition for receiving federal funding—to reject advertisements advocating the legalization of marijuana.

Some of these examples are instances in which the statute in question arguably encroached upon the executive branch’s authority. But in other cases—including the Truman, Kennedy, Johnson, Carter, and first and second Bush administration examples—the decision not to defend the federal statute was based on First Amendment, equal protection, or other civil rights–related arguments. And in all of these cases, the administration had solid legal reasons to believe that the statute in question was unconstitutional—whether or not those arguments ultimately prevailed in court. The Obama administration’s decision not to defend DOMA broke no new ground in that regard.

Government lawyers and legal scholars have long argued over the appropriate standard for the Justice Department to use when deciding not to defend a federal statute. The late Rex Lee, who held high posts in the Ford and Reagan administrations, said that the Justice Department should generally defend a federal statute unless it “would have the effect of limiting the President’s constitutional powers or prerogatives” or “is so patently unconstitutional that it cannot be defended.” Benjamin Civiletti, who led the Justice Department under President Carter, wrote that the attorney general “must exercise conscientious judgment” when the Constitution and an act of Congress come into conflict—recognizing that the answer may not be easy. President Obama’s attorney general, Eric Holder, said that the standard should be whether “reasonable arguments” can be made in the statute’s defense, but he added that the reasonableness standard does not compel the Justice Department to defend a law that targets minority groups for discriminatory treatment.

Never before, though, has the Justice Department declined to defend a federal statute when the arguments against the law are as threadbare as they are here. That’s what is so new—and so disturbing—about the attorney general’s announcement. Shifting the blame to the president’s predecessor simply will not work.