I can see why it is necessary for an elected government to have the power of eminent domain.
Well, can you also see the necessity for an elected government to have the power to coin money? If it was the policy of the Founders not to enumerate powers that were "obviously necessary," why did they bother enumerating so many powers that seem "obviously necessary?" Why didn't they just leave it for us to assume the Federal Government has all those powers, like you say they did with eminent domain?
The federal power of eminent domain is limited to taking property for federal public uses
Really? And just how do we know that? The same author who said that also said that we can just assume the Federal Government has powers it needs. What if it needs to take property for
private use? There is nothing in the Fifth Amendment which bars the Federal Government from taking property for
private use, or even requiring that if it does, it must provide compensation. By this reasoning, the Federal Government has all powers not prohibited to it by the Constitution, i.e., the exact inverse of Federalism, yet this makes no sense at all in light of the Tenth Amendment.
'The argument based upon the doctrine that the states have the eminent domain or highest dominion in the lands comprised within their limits, and that the United States have no dominion in such lands, cannot avail to frustrate the supremacy given by the constitution to the government of the United States in all matters within the scope of its sovereignty.'
Yes, "WITHIN THE SCOPE OF ITS SOVEREIGNTY." But what, precisely, is the scope of its sovereignty? Well, that's laid out in the Tenth Amendment. It has only that degree of sovereignty delegated to it by the States via the US Constitution. All other traits of sovereignty, without exception, are retained by the States and the people respectively.
If it is necessary that the United States government should have an eminent domain still higher than that of the state, in order that it may fully carry out the objects and purposes of the constitution, then it has it.
Well, we can just assume it has all powers it says it needs, then, and there was no point at all in enumerating the powers of the Federal Government. That was just a waste of ink.
The Fifth Amendment to the Constitution says 'nor shall private property be taken for public use, without just compensation.' This is a tacit recognition of a preexisting power to take private property for public use than a grant of new power.
So, this power rested with the Federal Government before the Bill of Rights was ratified? But the Tenth Amendment says it has only those powers delegated and enumerated. The Founders inform us that the Federal Government is not a State, but an association of sovereign States, possessing only those traits of sovereignty delegated to it by the States via enumerated powers in the US Constitution. How does that square with the presumption of sovereign traits not delegated? Can we presume that the UN has the sovereign power of eminent domain? It is a governing body to which we belong, and eminent domain is necessary to all government bodies, you say, so even though we never delegated to it said power within the United States, we must, by that reasoning, accept that it has that power if it feels the need for it in order to fulfill its function as a world governing body.
Aside from the implications of the 5th Amendment, probably or possibly the power derives from the first paragraph of Article 1, Section 8: "The Congress shall have Power to...provide for the...general Welfare of the United States..."
The general welfare of the United States is provided for by the means of constitutional government, i.e., by exercising delegated powers, as is made clear by Article 8 itself, otherwise why bother enumerating powers if the first paragraph of that enumeration was intended to function as a blank check made out by the States to the Federal Government?