Though he pledges not to take them himself, why is the president empowering his successors to take actions that he admits are un-American?

For many liberals, the ACLU fulfills a role akin to a canary in a coal mine: it's beyond the capacity of the average citizen to monitor every piece of legislation that might impact civil liberties, but when the organization starts freaking out it's taken as a credible signal that our rights are in peril. As America turned its calendars from 2011 to 2012, we witnessed that kind of moment. "President Obama's action today is a blight on his legacy because he will forever be known as the president who signed indefinite detention without charge or trial into law," said Anthony D. Romero, the ACLU's executive director. "The statute is particularly dangerous because it has no temporal or geographic limitations, and can be used by this and future presidents to militarily detain people captured far from any battlefield." Warnings are seldom so dire.

But there is an even more noteworthy signal that the National Defense Authorization Act, the bill in question, imprudently empowered the executive branch: the fact that President Obama himself concedes as much. "I want to clarify that my Administration will not authorize the indefinite military detention without trial of American citizens," he said in a statement released when he signed the bill. "Indeed, I believe that doing so would break with our most important traditions and values as a Nation." Put another way, our shortsighted president, knowing his own intentions, has assured us that he won't exercise powers in the bill that he regards as un-American, but doesn't mention that the restraint he vows won't bind future presidents one bit.

You'd think a litmus test presidents would use when bills come across their desk would be, "Does this empower my successors to do anything that would break with America's most important traditions and values?" You'd think if the answer were yes, prudence would demand a veto. But Obama has signed a bill that fails that very litmus test. This reflects badly on his judgment.

And a careful reading of Obama's language suggests his position is even worse than it seems. "Obama only promises not to put Americans into indefinite military detention," Marcy Wheeler observes. "I guess promising that Americans wouldn't be indefinitely detained, period, was too much of a stretch." She goes on to explain how another portion of Obama's signing statement actually undermines the one bit of the bill that civil libertarians could celebrate.

Sure as Obama argued in 2008 that indefinite detention is an affront to American values and an urgent precedent to overturn, he is going to campaign in 2012 as a president whose tough approach to fighting the War on Terror has resulted in a radically weakened Al Qaeda and a substantially safer homeland. The irony is that even as Obama makes the case that we're safer thanks to his policies, he's aggregating to the federal government ever more extreme powers, ostensibly justified by the terrorist threat, that impinge on our liberties more than ever before.

If we're really safer than we were during the Bush era, why should we trade even more liberty for the promise of safety, a trade-off that candidate Obama always insisted was a false one anyway?

It's the opposite of the change Americans were promised.