First, the POTUS cannot unilaterally replace the entire SCOTUS. The justices’ tenure is for life, subject to good behaviour. So, the POTUS would need the cooperation of all of the Justices to retire or the cooperation of both the House and Senate to impeach and convict each justice for poor behavior. This has never happened. The closest example of trying to replace the entire Court is FDR’s attempt to pack the court with justices who shared FDR’s view of the New Deal. FDR was consistently losing case involving New Deal programs by a vote of five to four and six to three. He attempted to have Congress approve the addition of four new justices to a total of thirteen. (The Constitution des not specify the number of justices for the SCOTUS. They have ranged in number from one to nine.) The justices feared a loss of power if FDR achieved his goal in packing the court. So, a few of the justices “saw the light” and started voting for the New Deal Programs. FDR stopped pursuing his goal to pack the court; it is unlikely he would have succeeded any way. Congress was not likely to give FDR this privilege.
Second, as to whether the country would be better off, it would depend on what you think the country should be in the first place, your view of constitutional interpretation (natural rights, original intent, precedent, a “living document”, etc.), and your views for general interpretations of statutes and rules. President-elect Obama would likely appoint justices supportive of his version of socialism; the same would have been true if Senator McCain had been elected. Certainly, having a court that supports the presdents’ views would make “change” easier, whatever that change may be. It would most likely eliminate or at least reduce the SCOTUS’s check on presidential power. I am not sure how much of a change this would be since the SCOTUS has been AWOL for twenty some odd years when it comes to checking the power of Congress and the President and limiting them to exercising the enumerated powers in the Constitution.
Third, an important part of any legal system is constancy. People, while kicking and screaming about bad laws (laws here meaning legislative acts, rather than laws and customs that naturally arise in a society), can at least adopt to “bad” laws and pursue happiness. If the law is regularly changing, it is hard for people to decide how to act. (I am setting aside for the moment a normative discussion on whether any of these laws and regulations can be good. Instead, I am working within the framework that there are laws (legislative acts) and conflicts over their interpretation. Currently, the rule of stare decisis, adherence to prior court decisions, gives some constancy to the interpretations of the Constitution, statutes and regulations. Each court out of deference to prior courts hesitates to make changes to constitutional, statutory and regulatory interpretation. A complete replacement of the justices on the SCOTUS with justices that President-elect Obama would approve would likely result in drastic changes. Admittedly, this is speculative. There is not much to back this up since the President-elect has been pretty quite about his views of the court and the “ideal” justice.
But, what causes me to speculate this way, is that he will not be alone in making these decisions and the constituencies that will be most involved will likely want justices willing to ignore stare decisis and over turn bad decisions in their view. For example, the ABA and ACLU will likely want justices who would strike down the PATRIOT ACT and limit invasions into our privacy; the NOW, ACLU, etc. will want justices that will further expand abortion rights by reversing SCOTUS’ decisions limiting abortion rights; and the Sierra Club and other environmental groups would want justices that would allow for expansion of environmental regulation.
So, if President-elect Obama were to completely replace the justices on the court, there would be great changes. Whether the country would be better off or not depends on your views of his porposed programs. As for me, the country is going to be worse off. If Congress stays loyal, then we may see the greaest shift towards socialism since President Nixon and certainly since FDR.
I hope this helps.