[quote=walterwhite]I doubt it was just one case on this clause. I can’t remember specifically but I’d bet we are talking about dozens of cases over many many decades.[/quote]
I don’t think it’s dozens, at least at the SC level. (I didn’t remember all this stuff, I looked it up.)
Primarily we have:
McCulloch v. Maryland from the early 19th century
which adopted Hamilton’s view of pretty expansive powers of congress, followed by some cases that more narrowly defined the general welfare clause, particulary objecting to lack of uniformity required in the first paragraph.
Then, after FDR packed the court, the following cases reinforced McCulloch:
Steward Machine Co. v. Davis
Helvering v. Davis
United States v. Butler
Interesting words from the Butler decision:
The clause confers a power separate and distinct from those later enumerated [,] is not restricted in meaning by the grant of them, and Congress consequently has a substantive power to tax and to appropriate, limited only by the requirement that it shall be exercised to provide for the general welfare of the United States. … It results that the power of Congress to authorize expenditure of public moneys for public purposes is not limited by the direct grants of legislative power found in the Constitution.