The Fifth Amendment's Taking Clause reads: "Nor shall private property be taken for public use, without just compensation." What should a textualist take this to mean? Could it mean what Professor Kerr suggests:
The text of the clause says that if private property is taken for public use, then just compensation must be paid. The Constitutional text doesn't address takings for private use at all. Not only would such a taking seem to be allowed by default, but the Constitutional text doesn't even seem to require the government to pay just compensation for it. The text doesn't say, "Private property shall not be taken for private use, nor shall private property be taken for public use without just compensation." It only says "Nor shall private property be taken for public use, without just compensation." Obviously there are good policy reasons why we might not want the Court to read the text this way, and there are also reasons why someone might or might not be a textualist. Still, if you're a textualist it seems that you're kinda stuck with that reading.
Quite frankly, I'm much too young to be a "textualist" or anything other than Mike. But as someone who takes seriously the Constitution's text, I offer my response.
A textualist still has basic assumptions when reading the text. One of these is that Congress is limited to enumerated powers. The Bill of Rights was not theoretically necessary, see Federalist No. 84, and if anything, says: "Congress you can't do these things anyway, but just in case you decide to get out of line, we'll preemptively remind you that you really-really can't do these things."
Under the reading of the Takings Clause Professor Kerr proposes, the Bill of Rights would enumerate further powers, since in not excluding private takings, it must therefore allow them. (Expressio unius est exclusio alterius). Instead, the text of Bill of Rights should be read as further limiting Congress' already limited power.
Thus, whether Congress has the power to take private property for private gain without paying just compensation should be answered elsewhere, e.g., does the Commerce Clause give Congress this power? The answer might be that Congress indeed, may take private property for private gain without paying just compensation, but if it does, the power comes not from the Takings Clause.
I realize that this form of textualism has its problems, as how can we determine what is a "basic assumption"? The 11th Amendment cases are an example of this problem -- It's "ahistorical literalism," according to Justice Scalia, to read the 11th Amendment literally, because states' immunity from suit is, at least to 5 members of the Court, a basis assumption of the Constitution.
UPDATE: Stuart Buck made similar points before I published this post, though I hadn't read his entry until now.