Then something changed.

The brief on the merits that Solicitor General Francisco filed in December took a surprisingly different line of attack on the Ninth Circuit’s decision. In addition to distinguishing Boumediene as inapplicable, the brief argues that Mr. Thuraissigiam’s claim must fail because the Constitution’s framers would not have applied the Suspension Clause to immigrants seeking relief from deportation. This is an aggressive “originalist” argument that comes very close to telling the court that Boumediene itself was wrongly decided. “This court has stated that ‘the Suspension Clause protects the writ as it existed in 1789,’ ” the brief asserts, citing an immigration case from 2001, Immigration and Naturalization Service v. St. Cyr. It continues: “And in 1789, the writ did not protect the sort of claim that respondent asserts here.”

To be generous, that is at best a partial rendering of what Justice John Paul Stevens said in his majority opinion in the St. Cyr case. Here is the relevant paragraph, highlighting two important words that the administration’s brief left out (Enrico St. Cyr was a Haitian immigrant trying to avoid deportation; he won the case):

“In sum, even assuming that the Suspension Clause protects only the writ as it existed in 1789, there is substantial evidence to support the proposition that pure questions of law like the one raised by the respondent in this case could have been answered in 1789 by a common law judge with power to issue the writ of habeas corpus. It necessarily follows that a serious Suspension Clause issue would be presented if we were to accept the I.N.S.’s submission that the 1996 statutes have withdrawn that power from federal judges and provided no adequate substitute for its exercise.”

Justice Kennedy voted with the St. Cyr majority. And in his majority opinion seven years later in Boumediene, he had this to say: “The court has been careful not to foreclose the possibility that the protections of the Suspension Clause have expanded along with post-1789 developments that define the present scope of the writ.”

What accounts for the administration’s aggressive advocacy in the face of the carefully nuanced precedents that apply to this area of the law? Two factors, I think. The first is that conservatives despise the Boumediene opinion. Judge Raymond Randolph, a stalwart conservative on the United States Court of Appeals for the District of Columbia Circuit, who wrote the opinion that the Supreme Court overturned in Boumediene, has openly been at war with the Supreme Court over Guantánamo.

In a 2010 speech to the Heritage Foundation, he compared the justices in the Boumediene majority to Tom and Daisy Buchanan in “The Great Gatsby:” “careless people, who smashed things up” and who “let other people clean up the mess they made.” And another conservative judge on the same court, Laurence Silberman, in a concurring opinion in 2011 called Boumediene “the Supreme Court’s defiant — if only theoretical — assertion of judicial supremacy.”

After Boumediene, dozens of Guantánamo detainees brought habeas corpus petitions in Federal District Court in Washington, and the judges of that court granted relief to many of them. But the conservative judges on the appeals court overturned one favorable ruling after another in what at least from the outside looked like a systematic effort to “clean up the mess” by rendering a potentially powerful rights-protecting decision toothless. Not once did the appeals court uphold a detainee’s grant of habeas corpus. Justice Brett Kavanaugh, who was a judge on the D.C. Circuit throughout that period, joined the majority in two of the more important cases.

The war on Boumediene is not ancient history. In his widely noticed speech to the Federalist Society in November, Attorney General William P. Barr took direct aim at the decision, referring to it as the climax of “the most blatant and consequential usurpation of executive power in our history.” According to the attorney general, the Supreme Court, in its series of Guantánamo cases, “set itself up as the ultimate arbiter and superintendent of military decisions inherent in prosecuting a military conflict — decisions that lie at the very core of the president’s discretion as commander in chief.”