One of the great mysteries — and ongoing controversies — of the Barack Obama presidency has to do with his record on civil liberties and counter-terrorism. In fact, for many former supporters of the president, it’s the alleged continuities between the anti-terror policies of Obama and Bush that first caused them to rescind their support for the former. Charges that Obama is worse than Bush, because he legitimized and gave bipartisan cover to that which was once seen as radical and divisive, are not uncommon.

So now that Obama is about to entire his final year in the White House, and now that attention is increasingly turning away from him and toward his would-be successors, it seems like an opportune moment to reassess the past seven years and figure out why, exactly, Obama’s record on counter-terrorism issues has been so controversial — and mixed. Which is where “Power Wars: Inside Obama’s Post-9/11 Presidency,” the new book from the New York Times’ Pulitzer Prize-winning reporter Charlie Savage, comes in.

Recently, Salon spoke over the phone with Savage about his book, which is both a deeply reported history of the Obama administration and a look at how bureaucracy, chance, politics and technology have so profoundly shaped its legacy. Alongside discussing what Obama really promised on the campaign trail in 2008, we also talk about the outsized influence of late-2009’s failed “underwear bomber,” and why the president has less control over the prosecution of leaks from his administration than you may suspect.

Our conversation is below and has been edited for clarity and length.

Before we get into the “underwear bomber” incident, which you argue was a much, much greater influence on the Obama administration than most people appreciate, I wanted to ask you to set the stage for the first year or so of Obama’s presidency. How did he conceive of these post-9/11 issues before Christmas, 2009?

Obama had been a big critic of the Bush administration reaction to the 9/11 attacks, of course, like a lot of Democrats. However, he was primarily criticizing those things like warranted surveillance and military commissions and torture and so forth from a certain vantage point. And kind of what we see now, which was harder to discern at the time of the Bush years, was that there were two very different strands of criticism among Democrats — and even among libertarians — of what the Bush administration did.

What were they?

There was the rule of law criticism, which said, “The president has to obey statutes. He can’t just blow through things like the FISA [warrant] requirements because he thinks it’s necessary and because he’s the Commander-in-Chief.”

And then there was the civil liberties critique, which was less interested in the legal process by which the policy was put in place and more interested in what is the relative role of the state in the “state power vs. individuals” [issue]. And these two strands kind of work together during the Bush years.

But they eventually start to diverge because the Congress in Bush’s second term started to adjust federal law to bring it into alignment with what [the government] was already doing under Bush’s direction. That at least dramatically reduces the rule of law problem; but the sort of individual [liberties] problem — if there is one — remains undisturbed by those changes.

And where does Obama land in the midst of all of this?

What you see when you go back and really parse Obama’s [campaign] speeches, and hear what the people he gathered around him once he went into the White House were saying, [it’s] almost all primarily in the “rule of law” faction. So other than torture, his mindset and that of the people he was gathering around him, coming into office, was: A lot of the stuff had been fixed. We had the [telecom immunity bill], which Obama voted for, which authorized a warrantless surveillance program; we had the Military Commission Act, and so forth.

There were a few more things that needed to be fixed or wound down or put on firmer legal grounding — and that was their task; to sort of finish the job of normalizing, regularizing and maybe even “rightsizing” the government’s response to the ongoing threat of terrorism. This was one of the things that he was going to do.

All right. So then Christmas Day, 2009, happens; the so-called underwear bomber. You argue that this was a big, big deal within the White House — bigger than many outsiders appreciate. Why was this failed attack so important?

That was a turning point for Obama. He’d already had some compromises and encountered things that were sort of harder in the real world than they seemed on the campaign trail, but he was basically on track to be doing what he wanted to do — or what he thought he wanted to be doing — coming out of that first year.

And then, on Christmas, 2009, an al Qaeda terrorist operative from Yemen — well, east of Nigeria, but fed by IEC, the mini-affiliate of al Qaeda — nearly brings down a jetliner above Detroit. It would have killed almost 300 people on American soil, on [Obama’s] watch. And so, number one, that’s a gut-wrenching moment; it was only sheer luck that the bomb didn’t go off. It was not that the system they put in place worked.

And then, the fallout from that was also tremendously important. Republican critiques that he was dismantling some of the things that Bush had put into place suddenly got a lot sharper; and the sense was, if there was another attack, and if it succeeded, the blood would be on his hands. And then underscoring all that is that Scott Brown, a Republican, wins Ted Kennedy’s Senate seat in deep-blue Massachusetts.

Right. That usually doesn’t get mentioned in this story. It’s usually seen as a major development in the story of the Affordable Care Act; not counter-terrorism policy. Why did it matter in that latter context, though?

The media at that time was portraying [Brown’s victory] as a reaction to Obamacare, but inside the Scott Brown campaign, the polls showed that it was really the terrorism issue that he got the most traction on. He was pounding on Obama and on his Democratic opponent for treating terrorists as criminals, for the fact that the underwear bomber had been read his Miranda warning and was being interrogated by the FBI and charged [in civil court] because Obama and Eric Holder wanted to bring Khalid Sheikh Mohammed and other 9/11 suspects from Guantanamo to New York and give them a civilian trial.

Brown kept pounding on the idea that these are terrorists and we shouldn’t give them these rights; and even in Massachusetts, at that moment, there was a certain wave of fear from the underwear bomber rolling across the country. It really resonated — and, suddenly, a Republican had won a Senate seat in Massachusetts. So inside the Obama administration, [it came to be believed that if] there is another attack, and it actually succeeds, Obama will be a failed, one-term president. He’ll lose, just like Jimmy Carter; and everything he came in there to do, including things that have nothing to do with national security, would fail.