SETH BARRETT TILLMAN: How Department of State v. Aids Vaccine Advocacy Coalition Should Be Resolved (But Probably Won’t Be).

A key issue in this federal case is: What are the legal consequences when Congress appropriates funds by statute? Here, Congress has appropriated funds for named organizations, but the President or his officers have chosen not to segregate and remove the appropriated funds from the Treasury.

Many believe, including some federal judges and legal scholars, that when Congress appropriates money by statute, it follow that those funds must be spent (leaving aside the possibility of any express discretion designed into the statute at issue). There are reasons to reject this position as a settled rule of law.

First, an appropriations statute authorizes the Executive Branch to segregate funds in the Treasury (if such funds are available) and to remove those funds from the Treasury, and, then, further authorizes that the funds be spent for the purposes or in the manner approved by Congress, and in no other fashion. See generally Paul Einzig, The Control of the Purse (1959). But it is not clear that an appropriation commands the segregation, removal, and spending of such funds. Whether a particular statute mandates the segregation, removal, and spending of such funds will depend on the words of the statute. In other words, a naked appropriation (even where made for a particular purpose) does not without more imply that Congress has left the Executive Branch without discretion not to spend the appropriated funds.

Much more at the link, including a little colonial-era history I didn’t know.