Professor Balkin continues the judicial activism discussion with a followup post defining his argument. I think I linked to his initial discussion a couple posts ago- but here is a wee tease of the second post (context: Jonah Goldberg wrote, in National Review, that liberals and not conservatives are judicail activists):

Jonah is under the delusion shared by many conservative pundits that the Warren Court is still in operation. It's not. Today conservatives control the judiciary and they are discovering the virtues of activism in all of its wonderful forms. This is the thesis, by the way of Keith Whittington's recent paper "The New Originalism." Whittington points out that originalists like Robert Bork argued for a jurisprudence of original intention because they thought it would deter what they considered to be the liberal activism of the Warren Court. But once conservatives took over the judiciary, Whittington points out, they developed a new use for originalism-- to strike down laws that they didn't like. The New Originalism is no longer aligned with judicial restraint; rather it's a tool of judicial activism. The point I was making to Jonah is that he is holding on to old fashioned stereotypes which haven't been adequate for some time. Today judicial activism is not the prized possession of wild eyed liberals: conservatives-- and especially today's conservatives-- are doing it too, and because they control the courts they probably have more opportunities. At the same time many liberal scholars and judges are rediscovering the virtues of judicial restraint, as you can see in their positions on areas ranging from campaign finance to affirmative action.
...Liberals have not been consistent about advocating judicial restraint precisely because their political ideologies cross cut with institutional concerns, and the same, I should add, is true of conservatives. My point in raising the example of Lochner was to remind Jonah, and now Stuart and Larry, of the long period of time in which it was the liberals who were complaining of judicial activism by conservative Justices and preaching judicial restraint; this was followed by a period in which conservatives like Robert Bork were attacking what they regarded as the judicial activism of the Warren Court and arguing for judicial restraint. My point was, and remains, that it is a big mistake to think that judicial activism is the modus operandi of any one political ideology. Political ideologies are quite often opportunistic with respect to institutional questions. Exhibit A is the Religious Right's demand for a constitutional amendment that would take the power to define marriage away from the states, where it has traditionally resided. In this example it seems clear that federalism concerns are yielding to ideological goals.
I want to endorse Randy Barnett's point that judicial activism is often an epithet hurled at decisions you don't like. That is the way that I understood Jonah Goldberg's use of the term-- he was, after all, writing a short op-ed piece on a blog; he was not engaged in a scholarly discussion of what the term might mean. When used as an epithet, people normally mean by "judicial activism" that a court is exercising judicial power in *unjustified* ways given their perspective of what the best interpretation of the Constitution is. That's what I understood Jonah Goldberg to be saying about liberals. And when I have criticized the Rehnquist Court's judicial activism, I have implicitly suggested that I think that those decisions are unjustified (which is, in fact, my view).

...If we define judicial activism in the way that Randy suggests-- as unjustified assertions of judicial power viewed from the perspective of the person making the charge-- then it follows rather easily that neither contemporary liberals or conservatives are committed to judicial restraint or judicial activism as a general rule. That is because the accusation of judicial activism is relative to a particular view of what the right interpretation of the Constitution is. Liberals and conservatives pick and choose whether they think courts should intervene or not in particular cases based on their larger political visions (restrained, as always, by the available modalities of constitutional argument). Because their visions are often opposed in these cases, they inevitably disagree in many cases about whether judicial power was exercised legitimately or illegitimately. Hence the liberals end up arguing for restraint when the conservatives argue for what in the view of liberals appears to be judicial activism, and vice versa. Remember that if judicial activism is defined as the unjustified or illegitimate use of the judicial power, then when liberals exercise judicial power in ways that conservatives think is unjustified conservatives will call it judicial activism, while when conservatives exercise judicial power in ways that liberals think is unjustified liberals will call it judicial activism. It is this feature of contemporary political and legal discourse that makes me deeply suspicious when someone like Jonah Goldberg offers casual aspersions about how liberals-- and not conservatives-- are judicial activists.

Well, that's more of a paste than I intended- but it captures much better than in my words, anything I could say. Like Balkin, the 'judicial activist' epithet is too carelessly and loadedly used to carry any meaning to the thinking person.