Power Line highlights the contradictory beliefs and statements of the Left regarding judicial behaviors:

…The Democrats say they need more time so they can “learn more about Judge Roberts’ judicial philosophy, especially on whether he will defer to precedent or seek to undo modern American jurisprudence that many conservatives say has been wrongly settled.” We hear this a lot; the Democrats worry that Roberts and other nominees might not adhere to the doctrine of stare decisis, which, in general, holds that courts should follow their own precedents rather than revisiting settled principles.
But the Democrats’ loyalty to the principle of stare decisis is highly selective. In fact, most of the decisions most beloved by liberals have overturned precedents that held the opposite. For example, in Lawrence v. Texas, which in 2003 discovered for the first time a Constitutional right to homosexual sodomy, the Court expressly overruled its own decision in Bowers v. Hardwick, which was decided as recently as 1986. So as far as the Democrats are concerned, stare decisis applies only after the Court has made a liberal ruling. Liberal rulings are carved in stone, whereas “conservative” rulings–those that represent the traditional understanding of our Constitution and laws, as written–can and should be overturned freely.
As Paul has noted, we aren’t sure exactly what Roberts’ judicial philosophy is. But we’re pretty certain it is more principled than the Democrats’.

Here are some previous postings which contain further suggestions for the proper role of the judiciary:
Judicial Activism: Commandeering the Public Debate & Violating the Founding Principles of America
“The Supreme Court Has Converted Itself From a Legal Institution to a Political One”
Are You an Originalist?
How Original Intent Does Not Equal Conservative Judicial Activism
The Ginsburg Precedent
Senator Schumer’s Double Standard
“Restoration of Judicial Restraint Assists the Restoration of Good Will, Because Democratic Governance Gives Everyone Their Say”
Rediscovering Proper Judicial Reasoning
Orrin Hatch: Don’t Overstate “Advise and Consent”
Senator Santorum: Judicial Activism is Destroying Traditional Morality
Relinking Constitutional Law & Jurisprudence to the Constitution
The Kelo Decision: When Private Property Rights are Eroded, Our Freedom is Diminished
Here are two examples of how the Left views the same issues:
Viewing the Supreme Court Nomination Battle From the Far Left
“We Are Going To Go To War Over This”
ADDITIONAL INFORMATION:
Here are other postings on this site about the related issue of the judicial filibuster debate:
The Filibuster…Continued
The Injustice of Smearing A Fellow American For Political Gain
The Senate Judicial Filibuster: Power Politics & Religious Bigotry
Mac Owen’s open letter to Senator Chaffee
Senator Mitch McConnell on the Judicial Filibuster
The Foolish Fourteen: An editorial by the former Dean of BU’s Law School
A Power Line overview of the filibuster debate
Revisiting the Case for Janice Rogers Brown