@blatham,
Actually, throughout American history, Presidents have used their disbursement authority in this way. Congress certainly has the fiscal appropriation authority. However, monies appropriated then need to be disbursed, and all the mechanisms for disbursement are under the control of the executive branch. Presidents have frequently "sat" on appropriated funds to get what they have wanted. Two classic examples of this are Eisenhower's threat to the Israelis in 1956, to pull their army out of the Sinai or they would not get one red cent of foreign aid from the United States. They left a lot faster than they had moved in invading Egyptian territory. Carter then used the technique to get Menachem Begin to come negotiate with Anwar Sadat at Camp David, and then to sign the accords negotiated there.
Sorry, but this is one of those rare occasions when Plump has (probably accidentally) the authority to act as he proposes. Somebody probably pointed this out to him, because you can bet he doesn't know these things. The money doesn't go away, it just sits there.