I agree with most of Orin's observations on Chief Justice Roberts' adherence to his credo of "judicial modesty" in Rapanos v. United States and Gonzales v. Oregon. Here are a couple more points that seem to have been ignored in the David Savage LA Times article Orin criticizes:
First, as I document in some detail here, the plurality opinion that Roberts joined in Rapanos and the dissent he signed on to in Oregon both strongly reaffirm Congress' power to do almost anything it wants within the relevant policy areas (water regulation and assisted suicide). That hardly strikes me as an aggressive assertion of judicial power.
Second, in Oregon, five of the six justices in the majority that held that the Controlled Substances Act did not permit the federal government to regulate the use of drugs to facilitate assistend suicide were also in the majority that had emphasized the "broad" and "comprehensive" nature of the CSA just a few months earlier in Gonzales v. Raich, where they also asserted the right of Congress to override "traditional" state prerogatives. This contradiction between Raich and Oregon was rightly emphasized by the dissenters in the latter case and virtually ignored by the Oregon majority. Despite this fact, I still think, as does Orin, that the Oregon dissenters voted the wrong way. But it is hard to describe their stance as "tak[ing] away the state's traditional power to regulate the practice of medicine," as Savage does. That bridge had been crossed in Raich, where most of the very same justices who made up the majority in Oregon voted to allow the federal government to override California's medical marijuana law. The latter had allowed doctors to prescribe the use of marijuana for medical purposes in much the same way as Oregon's Death With Dignity Act allowed them to prescribe the use of drugs to facilitate assisted suicide for the terminally ill.
Finally, Savage ignores Roberts' solo concurring opinion in Rapanos, which suggests that the Army Corps of Engineers could easily have obtained far broader regulatory authority under the Clean Water Act than the plurality opinion he signed onto would otherwise permit, simply by issuing new regulations that conformed to the Court's earlier interpretation of the CWA in SWANCC v. U.S. Army Corps of Engineers. Such regulations would, according to Roberts, have been entitled to "generous" judicial deference and could have given the Corps "plenty of room to operate." In sum, Roberts position in Rapanos was that the Corps has very broad discretion under the CWA's grant of power to regulate discharges into "navigable waters," but not the power to assert what he rightly called virtually "boundless" regulatory authority. The Corps had claimed the right to regulate virtually any body of water, no matter how small, remote, or nonnavigable, and had persisted in this stance in the face of an adverse Supreme Court decision. No broad assertions of judicial power here.
Overall, I think that Roberts voted the wrong way in Oregon, and I think that there are also flaws in his stance on Rapanos (though I believe that he got the bottom line more or less correct). But his positions were hardly contrary to "judicial modesty." Indeed, in my view, a stronger criticism of Roberts' performance is that he was too deferential to assertions of federal authority in both cases, particularly Oregon.