Obama Is Considering Doing Something Even Bush Didn't Try: "Preventive Detention" of People Who Will Never Get a Trial

The New York Times is reporting :

President Obama told human rights advocates at the White House on Wednesday that he was mulling the need for a “preventive detention” system that would establish a legal basis for the United States to incarcerate terrorism suspects who are deemed a threat to national security but cannot be tried...

“He was almost ruminating over the need for statutory change to the laws so that we can deal with individuals who we can’t charge and detain,” one participant said. “We’ve known this is on the horizon for many years, but we were able to hold it off with George Bush. The idea that we might find ourselves fighting with the Obama administration over these powers is really stunning.”

The other participant said Mr. Obama did not seem to be thinking about preventive detention for terrorism suspects now held at Guantánamo Bay, but rather for those captured in the future, in settings other than a legitimate battlefield like Afghanistan.

What justification could their possibly be for refusing someone a trial? Remember, there are well-established procedures for making sure that sensitive information which would actually detrimental to national security if released is kept away from the general public, such as "in camera" hearings (which is legal talk for a hearing held "in chambers").

Is Obama saying that an American citizen living inside the United States (America is presumably not a legitimate battlefield like Afghanistan - but see this) can be indefinitely detained without trial because Obama considers him a risk to national security?

What would constitute a risk to national security warranting detention? Revealing unlawful actions by the Bush administration? The Obama administration? Criticizing Obama?

Will the former constitutional law professor (Obama) use his knowledge of the law to safeguard the constitution, or - like the authors of the torture memos - to subvert it?

Update: Apparently Bush indefinitely detained prisoners as well.