Power of the Purse

As my "American Founding" course draws to a close, I can't help but see a parallel between the Federalist arguments and the current bill the Senate is expected to pass on funding for the War in Iraq. Congress is exercising its "power of the purse" by tying war funding to a timetable for withdrawal. I can only imagine Madison and Hamilton waiting to see another test of their separation of powers argument. The timetable reflects the will of the people (who voted in a majority of democrats largely to end the war) while the funding reflects Congress's control of spending. The president has a veto to ensure that Congress does not become a 'vortex' of power. The House bill passed with a vote of 218-208, not even close to the number required for an overturn of Bush's promised veto. The public who voted for Congress to vote against the Iraq War may be outraged, but the checks and balances are imposed to subdue the passions of the supposed less knowledgable public. Is this organization of power still valid?