WASHINGTON -- A pair of lawmakers on Thursday offered a bill that would repeal laws that allow the indefinite detention of Americans and others by the military without trial.

The power of military authorities to arrest and jail people as long as they want stems from Congress' 2001 joint resolution authorizing the use of military force against terrorists, but was explicitly codified into law last year after President Obama signed the National Defense Authorization Act on New Year's Eve. While allowing military detention of anyone, the act mandated that certain terrorist suspects had to be held by the armed forces.

Civil libertarians on the left and right were sharply critical of the law, even though the president promised not to grab Americans.

Obama set out policy rules last month making good on that pledge, specifying that U.S. citizens and numerous other categories of suspected terrorists would not be clapped into the military system, which somewhat mollified critics.

But many pointed out that those rules are only good as long as Obama is president, prompting Sen. Mark Udall (D-Colo.) and Rep. Adam Smith (D-Wash.) to offer their bill Thursday.

"On the books, we have a law that gives the executive branch the power to indefinitely detain people here in the U.S., even U.S. citizens, and we believe we should take that off the books," Smith said at a Capitol Hill news conference. "Even though you can make an argument that this executive will not exercise that authority, has not exercised that authority, we don't believe we can afford to allow that kind of power to reside in the executive branch."

"That policy won't tie the hands of future administrations," said Udall. "I continue to believe that the NDAA detention provisions weaken our national security and our constitutional protections."

"I believe the U.S. military should be focused on getting the bad guys overseas, not getting involved with law enforcement here on U.S. soil," Udall added.

Proponents of the law argue that leaving anti-terrorism efforts up to civilian law enforcement authorities makes it harder to extract vital intelligence that could prevent a devastating attack at home. They say that the United States is engaged in a war and that the military is best equipped to deal with war-related criminals. They note that the law makes it clear that the battlefield has extended to America's shores. And they contend that any enemy -- citizen or otherwise -- should be treated as such, and not as a criminal defendant with the attendant rights.

At their press conference, however, Smith and Udall argued that civilian law enforcement has been extremely successful in handling terrorists, prosecuting more than 400 suspects, compared to only a handful tried in the military system.

"Traitors must be dealt with, but even in our darkest hours we must ensure that our Constitution prevails," Udall said. "Our Constitution, I believe, is in many ways the most powerful weapon we have against those who would do us harm. We can't afford to erode our liberties. In the end, that would leave us even more at risk."

Last year's passage of the NDAA has sparked intense debate since, with people differing over what it actually accomplishes.

Many defenders of the administration argue that the 2001 Authorization to Use Military Force already permitted indefinite detention.

Their case is bolstered by the fact that the Supreme Court has not ruled in the cases of American terrorist suspects who were captured and held by the military, while lower courts have found such detentions to be lawful. Those cases, including that of Brooklyn native and would-be dirty bomber Jose Padilla, were rendered moot after the suspects were transferred for civilian prosecution.

Others argue that NDAA sections 1021 and 1022 take matters a step further by mandating military detention in many cases. Indeed, Obama saw fit to clarify that his administration would not interpret the law to sweep in citizens and several other categories of suspects.

The Udall-Smith bill would both repeal the NDAA detention provisions and bar the detention powers first asserted by the Bush administration under the 2001 Authorization to Use Military Force.

"Even if last year's NDAA hadn't happened, this bill would be necessary in order to reverse that -- in order to say no, indefinite detention, military custody, military courts are not an option for people arrested here in the U.S.," said Smith. "We're trying to undo what they were doing last year, pushing in the wrong direction, and also get it back to where it should have been."

"We have to make these changes. ... Our Constitution has stood us in good stead," Udall said. "It's why the rest of the world looks to us as a role model."

The legislators hope to add their measure as an amendment to next year's defense authorization bill, which is likely to be a difficult task. One administration official said it did not look like the Senate in particular had the stomach for dealing with the measure in an election year.

But the two legislators said they were optimistic, considering the level of outrage and energy generated in last year's debate. They suggested the White House was on their side in spirit, if not yet in deed.

"They're sympathetic to our effort to make some fixes here, but they have not taken a position yet on this specific piece of legislation," Smith said.

Michael McAuliff covers politics and Congress for The Huffington Post. Talk to him on Facebook.

