Honestly, the legislative branch can take most of the power anytime it wants. The Supreme Court interprets laws when they are vague, or when they are unconstitutional. It is loathe to consider things unconstitutional when they are plainly constitutional. But the deep division in American politics has resulted in a legislature that is almost incapable of considering major legislation that has lasting impact on Americans, much less passing it. They can certify a stamp or name a post office anytime, but something with as many moving parts as Obamacare was nearly a decade in the making and barely lurched over the finish line as a crude simulacrum of the original plan.
There's a reason Congress tends to enjoy a low-teens approval rating on aggregate (all Americans continue to vote the same legislators back into office year after year after year).