Andy McCarthy makes the case for the indefinite detention power Reid mentions below, and provides some useful and mitigating context. Obviously there is a legitimate national security interest in being able to detain American citizens who join anti-American terrorist organizations, and there are circumstances where civilian courts may not be up to the job.
But even if the intent of the legislation would leave the civil liberties of an overwhelming majority of Americans untouched, the checks and balances are inadequate. Even if we accept McCarthy’s analysis of the McCain-Levin agreement in full, we have to assume a.) that the government will never make a mistake and b.) the government will never abuse its power. These are not very tenable assumptions, which is why the Founding Fathers were wise not to make them.
The law-enforcement paradigm may not always be ideal for dealing with terrorism. But conservatives need to grapple with the civil liberties implications of having a war with no battlefield and no identifiable end date. Their need to be safeguards to ensure that policies designed to detain or kill terrorists do not detain or kill innocent American citizens.