I dispute the premise of the first paragraph. Congress passed the FTC Act precisely to give the executive latitude to go after monopolies and other anti-competitive practices without the need for congress to hyper-specifically define them. At the same time, a number of House and Senate members are working to pass legislation to plug the gaps left by the Sherman/FTC Acts. Congress setting up a broad legislative regime and then delegating power regarding the specifics is exactly how the system is supposed to work.