In the confirmation hearings for John Roberts, Roberts has insisted that his overarching principle is the rule of law. An important part of his responses to questions from the committee have been to distinguish between law and policy on the one hand, and hubris and humility on the other. Roberts tends to say that a judge should be about holding up the law and not making policy, and that in doing so a judge should be humble and not exhibit the arrogance that his policy preferences should masquerade as law. In short, the judge must uphold legal precedent and not overturn rulings due to policy preference.
Judicial restraint rather than judicial activism --- unfortunately, the Senators asking most of the questions confuse law with policy, and want a judge on the Supreme Court to uphold policy preferences that were made law through generations of judicial activism. So the idea they want Roberts to commit to now is that judicial humility will prevent him from reversing law that was adopted against precedent 25 years ago. After Bork, judicial nominees know that to answer that question definitively means the end of their chances of getting approved. There is also an issue that judicial restraint does limit change to adjustments on the margin rather than wholesale shifts in legal rules.
The point I want to stress, however, is not the politics of Supreme Court nominations. Instead, the social scientific issue is the impact of alternative legal regimes on the performance of an economic system. A reasonable reading of The Road to Serfdom could contend that F. A. Hayek postulated that the rule of law constituted a "factor of production." When the "rule of law" is undermined (as would occur under socialist policy), the resulting regime uncertainty will destroy the economic environment --- time horizon of investment will collapse, incentives for husbanding resources will disappear, and gains from exchange will go unexploited. For an examination of this proposition see the paper by John Robert Subrick and myself that was published in the Supreme Court Economic Review and for an overview of Hayek's legal theory see this paper written by Scott Beaulier, Chris Coyne and myself published in the NYU Journal of Law and Liberty.