President Obama's speech was a clear rebuke to his fellow speech-maker, Dick Cheney - and to the Bush administration as a whole.
Mr Obama made a number of references to Republicans who disagree or have disagreed with the former vice-president's approach to national security.
He referred (although not by name) to former Secretary of State Colin Powell and quoted two Republican senators, Lindsey Graham and John McCain.
And he emphasised that this had been a bipartisan rejection, by referring to the nomination by the American people of presidential candidates from both parties who wanted to turn the page on harsh interrogation techniques.
In a phrase that his political opponents are certain to seize on, Mr Obama said the techniques that were used were "not America".
Above the fray
His one olive branch was confirmation that he would not support a "truth commission" looking into the past.
He recognised the practical difficulties in closing Guantanamo - and, while he avoided giving details of which detainees would be transferred and when, he took some time to lay out clearly the different categories of remaining prisoners.
They range from Uighurs (whom the courts have already ordered to be released) to the dangerous prisoners who will not be taken in by other countries.
At times Mr Obama seemed to have his former law professor's hat on. He was attempting to counter emotion with logic and - as he put it - "a dose of common sense".
US prisons, he pointed out, already house hundreds of terrorists and no-one has ever escaped from the high security "Supermax" prisons where convicted Guantanamo inmates are likely to serve their sentences.
His early reference to his parents and to the "more perfect union", as well as his decision to hold the speech in the National Archives, where the US Constitution is kept, had rhetorical and symbolic echoes of the campaign speech on race he made in Philadelphia.
It suggested that - once again - he was attempting to rise above the political fray and make a wider point about national security.
Again, he positioned himself as a man of unity - saying that national security should unite the country, not divide it.
That, too, was an implicit criticism of how the Bush administration reacted after 9/11.
By ending the speech with a long passage on the Constitution, with references to secession, segregation and the Cold and World Wars, he was placing the present challenge in the context of the sweep of history.
It is a tradition after set-piece speeches in US politics for the opposition party to offer a rebuttal.
Today was no exception, with Dick Cheney, the former vice-president - and target of much of President Obama's rhetoric - setting out his own, alternative vision of national security.
It was a vision in which the "enhanced interrogation techniques" were an appropriate response and the current president's pragmatism an insufficient and dangerous course of action.
It was not intended to be a rebuttal - Mr Cheney's speech had been scheduled some time in advance.
The fact that the White House chose to put the president up against him was an acknowledgment that, while he is a divisive figure, the former vice-president has helped to influence the debate - and, in the process, to rattle some Democrats.
It was also a sign that they felt that offering the American people - and Congressional Democrats - a stark contrast in styles and content, would help frame the debate as a choice between the past and the future; enhancing public and political support for the president's approach.
In his speech, Mr Obama addressed the main concerns of Congress, with his clear commitment not to release prisoners who pose a security threat to the country onto US soil.
He had his former senator's hat on when he referred to the ease with which the Guantanamo issue can be made into 30-second political commercials.
But he also issued a challenge: reminding members of Congress, including those from his own party, that they, too, had pledged to abide by the US Constitution and America's core values.
It was an implicit call for them to show backbone, in the face of Republican - and Dick Cheney's - attacks on the Guantanamo policy.