The key reason the legal challenge has proceeded through the courts is because Congress has failed in its duty to check this expansion of executive power. If it were remotely interested in providing meaningful oversight as a body, this challenge would not be before the Supreme Court. However, Congress is entirely subservient to the interests of the national security state and unmoved by concerns of Americans, who oppose violations of civil liberties or the idea that one has to choose between security and liberty. So, the plaintiffs have advanced this case as a last-ditch effort to disrupt the unchecked expansion of the surveillance state in America.
Kevin Gosztola, Despite Hurricane Sandy, Supreme Court Hears Argument Over Whether NSA Warrantless Wiretapping Can Be Legally Challenged