Final answer:
The delegation of the power of eminent domain to the U.S. Postal Service for acquiring land in rural communities is an appropriate exercise of constitutional power.
Step-by-step explanation:
Under the Fifth Amendment of the United States Constitution, the government is empowered to exercise the power of eminent domain and take private property for public use.
The courts have traditionally upheld the government's right to use eminent domain when the property serves the public good and owners are provided with just compensation.
Since Congress has the power to establish post offices and post roads, the delegation of the power of eminent domain to the U.S. Postal Service for acquiring land for new post office facilities in rural communities is an appropriate exercise of constitutional power.