In U.S. v. Butler, 297 U.S. 231 (1936), the Court has a concise and fairly non-technical discussion of the two main positions on the spending clause in the early time of the U.S. I’m pretty sure that there are several websites which the general public can use to access U.S. Supreme Court decisions. (I can provide additional case citations as well, if you’re interested.)

There’s also a decent discussion at: http://caselaw.lp.findlaw.com/data/constitution/article01/26.html (Discussion of the “spending clause” begins about half-way down the page.)

Also, Philip B. Kurland and Ralph Lerner reproduce twenty-eight different discussions from the founding era on the spending clause (and some on the so-called taxing clause, which is also cl. 1, but raises slightly different questions than does the spending clause) in vol. 2 of THE FOUNDERS’ CONSTITUTION (University of Chicago Press 1987), pp. 407-470.

I’m always happy to chat via e-mail as well. Although I’m no expert on the spending clause itself.

It’s called the “spending clause” and reads: “The Congress shall have power to lay and collect taxes . . . to . . . provide for . . . the general welfare of the United States.”

So the national government can use it spending power to achieve ends consistent with what Congress deems to be the “general welfare” of the nation, even if Congress does not have the authority to regulate the matter directly under the subsequent powers granted in art. I, sec. 8.

So, e.g., Congress may not directly legislate a national drinking age under its art. I, sec. 8 powers (because that power is not delegated to Congress), but it can use its spending power to provide incentives and inducements to achieve ends indirectly that it cannot achieve directly.

As I mentioned, the Jeffersonians hotly constested this reading of the Constitution from the start, arguing that the art I, sec. 8, cl. 1 spending power authorizes spending only for the powers subsequently delegated to the national government in art. I. sec. 8. There are some interpretive problems with the Jeffersonian view, but they’re a bit “inside baseball” to go into here.

And, of course, there’s no problem at all with states making exceptions in their drinking-age laws for military personnel. I’d like to see the national government try to yank transportation funds from any state that made such an exception.