Spending for the general welfare predates FDR and the new deal.
+1; I was trying to reflect the fact that the courts have been much more consistent in their rulings since then. During the late 19th and very early 20th century, the SCOTUS went back and forth on the issue with a series of rulings, some of which were muddled and contradicted one another. It is true, however, that since the very beginning, Congress has been authorizing spending programs that go beyond the explicit scope of the Constitution in some way or another, but most of these programs were relatively small in scale compared to the New Deal and did not get directly challenged in the courts.
It's also true that Alexander Hamilton was an early advocate of a relatively unrestricted spending power. FWIW this debate goes all the way back to the drafting of the Constitution; some of the founders did not want to include the phrase "general welfare" in the document at all, for precisely this reason.
However, going back to my earlier argument...
Spending tax monies on a program that benefits citizens across the USA more or less equally has generally been held as constitutional under the Taxing & Spending Clause.
The problem is that the mandate is
not a tax spending program, and it's being justified under the Commerce Clause using specious reasoning.