In a discussion of the privacy line of cases (Griswold-Lawrence), a constitutional law classmate remarked that he didn't see why we didn't just use the 9th Amendment -- "The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people" -- to avoid the textualist problem of privacy rights' being penumbral. To say that the states could deny all rights that were not specifically enumerated in the Constitution surely conflicts with the 9th.
I replied that this would give us a libertarian constitution, which he initially didn't see as a bad thing until I pointed out that such a constitution might also deny government the ability to regulate economic liberties. The right of contract is also an unenumerated "right," and it would appeal to originalists as being much more likely to have been contemplated by the elite white males who wrote the 9th than the right to contraception or abortion.
Since the New Deal, the federal government has regulated economics through the necessary and proper exercise of commerce clause power (Darby, Wickard). If contract were raised to the same fundamental right level as privacy, Congress would face a much higher standard (strict or at least heightened scrutiny) in setting the minimum wage or maximum hours than the current rational basis test demands. Assuming incorporation, so would states that sought to regulate the same matters for the sake of the general welfare -- if they even wanted to make such regulations, as many states likely would have a "race to the bottom," setting the lowest minimum wage and highest maximum hours in order to attract business.
In short, those who want to guarantee certain social liberties, but not economic ones, should look at who supports renewing the 9th Amendment -- most prominently of late, Randy Barnett -- before deciding that it's their new best friend. If the 9th Amendment is not an inkblot, it appears to have the potential to be a can of worms.