When you don't have an argument, you can always just beg the question:

As a young senator involved in judicial nomination debates, Obama showed no deference to presidential choices. Instead, he developed a theory that Supreme Court justices should favor socially unfavored groups. He opposed John Roberts for using his skills "on behalf of the strong in opposition to the weak." He criticized Samuel Alito for siding with "the powerful against the powerless." Obama made these distinguished judges sound monstrous because they stood for the impartial application of the law.

That's Michael Gerson.  The jeune Obama has obviously alleged that the judges were "partial" to the interests of the powerful.  Obama is not, in fact, referring to Roberts's behavior as a judge.  But that's another point.  If one reads the whole passage (and not just the heavily elided selection featured on right-wing blogs), Obama addresses Gerson's "impartial application of the law" objection:

There is absolutely no doubt in my mind Judge Roberts is qualified to sit on the highest court in the land. Moreover, he seems to have the comportment and the temperament that makes for a good judge. He is humble, he is personally decent, and he appears to be respectful of different points of view. It is absolutely clear to me that Judge Roberts truly loves the law. He couldn't have achieved his excellent record as an advocate before the Supreme Court without that passion for the law, and it became apparent to me in our conversation that he does, in fact, deeply respect the basic precepts that go into deciding 95 percent of the cases that come before the Federal court — adherence to precedence, a certain modesty in reading statutes and constitutional text, a respect for procedural regularity, and an impartiality in presiding over the adversarial system. All of these characteristics make me want to vote for Judge Roberts. 

The problem I face — a problem that has been voiced by some of my other colleagues, both those who are voting for Mr. Roberts and those who are voting against Mr. Roberts — is that while adherence to legal precedent and rules of statutory or constitutional construction will dispose of 95 percent of the cases that come before a court, so that both a Scalia and a Ginsburg will arrive at the same place most of the time on those 95 percent of the cases — what matters on the Supreme Court is those 5 percent of cases that are truly difficult. In those cases, adherence to precedent and rules of construction and interpretation will only get you through the 25th mile of the marathon. That last mile can only be determined on the basis of one's deepest values, one's core concerns, one's broader perspectives on how the world works, and the depth and breadth of one's empathy.

In those 5 percent of hard cases, the constitutional text will not be directly on point. The language of the statute will not be perfectly clear. Legal process alone will not lead you to a rule of decision. In those circumstances, your decisions about whether affirmative action is an appropriate response to the history of discrimination in this country or whether a general right of privacy encompasses a more specific right of women to control their reproductive decisions or whether the commerce clause empowers Congress to speak on those issues of broad national concern that may be only tangentially related to what is easily defined as interstate commerce, whether a person who is disabled has the right to be accommodated so they can work alongside those who are nondisabled — in those difficult cases, the critical ingredient is supplied by what is in the judge's heart.

I talked to Judge Roberts about this. Judge Roberts confessed that, unlike maybe professional politicians, it is not easy for him to talk about his values and his deeper feelings. That is not how he is trained. He did say he doesn't like bullies and has always viewed the law as a way of evening out the playing field between the strong and the weak.

I was impressed with that statement because I view the law in much the same way. The problem I had is that when I examined Judge Roberts' record and history of public service, it is my personal estimation that he has far more often used his formidable skills on behalf of the strong in opposition to the weak. In his work in the White House and the Solicitor General's Office, he seemed to have consistently sided with those who were dismissive of efforts to eradicate the remnants of racial discrimination in our political process. In these same positions, he seemed dismissive of the concerns that it is harder to make it in this world and in this economy when you are a woman rather than a man.

As I tell my Critical Thinking class, it's just not that hard.  I just don't understand why Gerson can't do what every phil 101 student must do in order to earn a C.