of thing. While it is true that money is fungible, it isn't difficult to put rules (or laws) in place to clearly separate and segregate funding from different sources and treat them uniquely.

For example, in the football donation example above, you could put a rule in place that says general athletic funds are split according to a specific pre-set formula that is independent of any donations made for a specific sport. This would make it difficult for a football-specific donation to indirectly fund another athletic endevour, at least in the short term.