The fact that the aid is only for specific purposes.
Explanation:
After World War II, all the states have to trust on federal money. The term Grants-In-Aid is related to the federal government helping the states with a given amount of money for a particular reason. However, there is another type of help which is called Block Grants, that is, the money received by a state with few restrictions and strings attached. This is what might keep some states from accepting a grant-in-aid, since they receive the money for a specific purpose and directions on how the money should be better spent.
