> Thus, in certain extraordinary cases, both separation of powers principles and a practical understanding of legislative intent make us “reluctant to read into ambiguous statutory text” the delegation claimed to be lurking there. To convince us otherwise, something more than a merely plausible textual basis for the agency action is necessary. The agency instead must point to “clear congressional authorization” for the power it claims.
I can find nowhere where they say that Congress cannot delegate broad powers, only that it's not obvious that Congress did or that they intended to. Do you have a citation to the contrary, or are you making assumptions based on the news coverage?