[inquest]

I'm still trying to figure out how the executive branch can unilaterally "change" an act of Congress in the first place.

[dirtboy]

I'm still trying to figure out how the executive branch can unilaterally "change" an act of Congress in the first place.

I would venture that it lies in the process of converting laws into rules. Congress passes a law, and the executive branch develops rules for interpreting that law. Within that framework, there is a certain degree of latitude for adjustments to policy, depending upon the opinions and biases of a given administration.

[Steve_Seattle]

"I'm still trying to figure out how the executive branch can unilaterally "change" an act of Congress in the first place."

I think it is because Congress passes laws which are implemented - in some cases - by agencies of the Executive Branch (the EPA in this case), and those agencies have certain discretionary powers carrying out the legislative mandate. The legislation itself doesn't always specify all the details of what is to be done, but empowers the relevant agency to formulate specific regulations to carry out the objectives of the legislation. That's how I understand it . . .