Jack Goldsmith writes: When Michael Ratner argued in a February 2002 lawsuit that British citizen Shafiq Rasul had a legal right to challenge his detention at Guantanamo Bay, there was little reason to believe he and his colleagues at the Center for Constitutional Rights (CCR) would play any role in shaping America’s national security landscape. The country was still seething with anger over the attacks of 9/11, and longing for revenge. The few legal precedents that existed were not very encouraging. (“Never in American history had the [Supreme] Court tried in any way to interfere with a war in progress,” noted Arthur Schlesinger Jr. in The Imperial Presidency.) And the Ratner-led CCR was a far-left legal advocacy organization—the group had previously represented the Attica rioters, the Chicago Eight, Nicaraguan contras, and assorted other “violent radicals, Communist front-groups, cop-killers, and sworn enemies of the United States,” in the words of conservative critic Marc Thiessen—that had few friends in the Washington, D.C. establishment.

And yet, a decade later, it’s now clear that Ratner and progressive activists like him have had an outsized impact on national security policy—though not exactly the one they would have wished. CCR would win landmark Supreme Court cases that challenged executive authority. But those achievements came at an unexpected price: They ultimately helped cement the political and legal consensus in support of the counterterrorism policies that emerged at the end of the George W. Bush administration, and they enabled Barack Obama to continue those policies. By successfully challenging the government’s authority, Ratner and his friends mostly ended up strengthening it. In that irony lies the most important constitutional lesson of the last decade.

By June, 2004, Ratner’s hail-mary lawsuit had produced a famous Supreme Court victory. That month the Court set off on a new course in American history by holding that Rasul and every other detainee at GTMO could challenge in court “the legality of the Executive’s potentially indefinite detention.” The Rasul litigation led the Bush administration to tighten its detention standards and contributed to the discharge of 308 detainees from GTMO. More broadly, as Justice Antonin Scalia predicted in his dissent, the decision precipitated the projection of “the cumbersome machinery of our domestic courts into military affairs.”

It was a high-profile win, and the antiestablishment activists at CCR were soon bombarded by pro bono offers from hundreds of attorneys, including many from America’s most elite law firms. These lawyers—who came to be known as “the GTMO Bar”—quickly flooded federal courts with habeas corpus petitions from detainees seeking release. That initiated a series of convoluted legal and political battles that ultimately seemed to affirm their efforts. Congress enacted laws in 2005 and 2006 that extinguished habeas corpus rights and replaced them with a system of military and judicial review. But the Supreme Court, in the summer of 2008 in a case called Boumediene, declared that habeas corpus must apply to GTMO as a matter of constitutional law. It was the first time that the Court had invalidated a wartime measure that had the support of Congress and the President.

In the heady days after Boumediene, Ratner and his colleagues, the momentum on their side, assumed that the GTMO detentions would not survive judicial review. They grew more confident when former constitutional law professor Barack Obama—who as a candidate had campaigned against George W. Bush’s counterterrorism policies, and who had received an endorsement from 70 members of the GTMO Bar—was elected president. Some at CCR predicted that the Guantanamo Bay facility would be closed within the year. “Rule of law, baby!” they shouted on Obama’s inauguration night.

We now know that things would not turn out as the GTMO Bar hoped. Ratner and his colleagues overestimated the civil libertarian commitments of Barack Obama and misunderstood how the burdens of the presidency would affect his judgment. They also underestimated the breadth and depth of the legal consensus in favor of executive authority.