Goodwin Liu is exactly the kind of person I want on a federal appeals court. He's solidly left-leaning on social issues and, unlike anyone currently on the Supreme Court, he argues that courts have an obligation, under the Fourteenth Amendment, to preserve a basic safety net. That's old-school judicial liberalism of the type William O. Douglas, William Brennan and Thurgood Marshall propounded in the 1970s, and hasn’t been seen much since, and it’s a very necessary counterbalance to the judicial right's revival of the New Deal vintage argument that the Constitution necessitates laissez faire economic policy.

Which, if I were a conservative senator, would be a very, very good reason to oppose his nomination. That’s why I don’t buy Adam Serwer’s argument that the Senate GOP's effort to block Liu's nomination to the Ninth Circuit Court of Appeals is just petty revenge for Liu's opposition to the confirmation of Justice Samuel Alito. The United States has a system of government where courts have, de facto, an important policymaking, or at least policy-altering, role. I think that's a good thing, provided courts keep up their recent role as protectors of minority rights, but you can make a case, as Jeremy Waldron, Mark Tushnet and others have, the other way.

But insofar as judges have that kind of policy role, it's totally legitimate to evaluate them in terms of their views on policy. The Senate GOP is wrong to block Liu because he is right about policy, not because his policy views should be shunted aside.

Dylan Matthews is a student at Harvard and a researcher at The Washington Post.