I was traveling last week and missed this Radley Balko article, in which he argues that the president should not order the Solicitor General to defend laws he believes to be unconstitutional before the Supreme Court, as President Obama recently chose to do with the Defense of Marriage Act:

The usual response to criticism of an administration’s positions in Supreme Court cases is that the solicitor general’s mission is to advocate on behalf of the government. It only makes sense, then, that the office would regularly urge federal appeals courts to limit constitutional rights and expand the powers of police and prosecutors. This was the conventional wisdom during the confirmation hearings for Justice Elena Kagan, whose defenders cautioned against drawing conclusions about her positions on constitutional rights and criminal law based on her work as solicitor general. When Chief Justice John Roberts was asked at his own confirmation hearings about positions he took while working in the Office of the Solicitor General during the Reagan administration, he replied that as a Supreme Court justice he probably would approach those questions differently than he did as a legal advocate whose client was the federal government.

It is true that the solicitor general’s role conventionally has been understood in this way. But I’m not convinced that it ought to be. As a client, the federal government is quite different from an accused murderer or a patient in a medical malpractice case, because it is supposed to represent the interests of all Americans. And while it’s true that one of the president’s main responsibilities is to enforce the country’s laws, he also has a duty to uphold and defend the Constitution, which is not the same as latching onto whatever interpretation of the Constitution favors the government.

Imagine a president who is elected on a platform that stresses the Bill of Rights, arguing that the government routinely flouts the Fourth Amendment and disregards the rights of criminal defendants. (Bear with me here.) According to the conventional view of the solicitor general’s role, the idealistic new president would be expected to staff the office with the country‚Äôs brightest legal minds and task them with convincing the Supreme Court to interpret these constitutional protections as narrowly as possible.

I agree with Balko that the president should not support laws he believes to be unconstitutional, but what he doesn’t explore is the similarity of this idea to the doctrine of nullification wherein states refuse to enforce laws their legislators or voters believe to be unconstitutional. True, failing to defend a law before the Supreme Court is less radical than refusing to enforce it–as nullification would demand–but it grants the idea that the federal judiciary is not, and should not be, the sole arbiter of constitutionality. If the Solicitor General was no longer expected to defend all federal laws, it would give the president the ability to launch a constitutional review of all federal legislation.

Some may worry that this increases an already powerful executive, but the key difference between this and other recent assertions of executive power such as signing statements and warrantless wiretaps is that this is a purely negative power. The president cannot expand the power of the federal government with this power; he could only limit it. The net effect would be fewer laws in effect, and I fail to see how any supporter of limited government–or anyone with a minimum of sense, for that matter–can see that as a bad thing. Does anyone really believe that what this country needs is an increasingly complex legal code?

If we want to constrain the power of the government, we need to give more institutions–the president, state legislatures and electorates, etc.–this kind of constitutional veto over federal legislation. It’s abundantly clear that the extant checks on federal power have failed, and nothing in the Constitution forbids presidential or state nullification, so why fight new impediments to federal power?