Chip Mellor provides a good lesson in the U.S. Constitution in his Forbes opinion article, An Unhealthy Exercise of Power. Here’s a key excerpt (emphasis mine):
Congress claimed the power to enact PPACA [Obamacare] under the Commerce Clause of the Constitution, which says in its entirety that Congress shall have the power “to regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes.” The clause was placed in the Constitution to avoid balkanizing the new nation by giving Congress the power to prevent states from erecting trade barriers.
That is essentially how the clause functioned for 150 years. But in 1938 the U.S. Supreme Court decided the case of Wickard v. Filburn, which upheld a New Deal law allowing the secretary of agriculture to establish an annual national acreage allotment for wheat all the way down to individual farmers.
The Court effectively amended the Constitution by turning the Commerce Clause into an affirmative grant of federal authority allowing Congress to regulate any economic activity that has a “substantial effect” on interstate commerce.
I recommend reading the whole article.
For those who think the Supreme Court has the power to amend the Constitution, all I ask is to direct me to where that power derives from and explain to me how that power coexists with the Constitutional Amendment process defined in Article V. While there is a fine line between interpreting and amending, they are not the same.