President Obama's decision this week not to defend the Defense of Marriage Act (DOMA) in court demonstrates both contempt for the law itself and a disturbing arrogance concerning his own authority.

This action is not unique. As today's Wall Street Journal notes, "The White House has apparently decided that it won't enforce the unpopular parts of its health-care plan until after the 2012 election. The latest evidence is its decision not to slash Medicare Advantage, the program that Democrats hate because it lets seniors choose private insurance options."

And this week's decision regarding DOMA is not a new departure from allegiance to the law. As George Will wrote in 2009, "The Obama administration is bold. It also is careless regarding constitutional values and is acquiring a tincture of lawlessness."

The President of the United States takes an oath when he assumes office, assuring us that he will "defend the Constitution of the United States." That Constitution makes Congress the legislative body, not the Executive branch. Thus, when Congress passes legislation that is signed into law by the President, it becomes incumbent upon the President -- as the chief constitutional law enforcement office in the nation -- to defend it.

When this or any President refuses to defend any given law, he is placing himself above it. How, in principle, this distinguishes the United States from any tin-pot autocracy, where law is made by the fiat choices of an unaccountable dictator, escapes me. For that matter, why bother with having legislative (Congress) or judicial (the Supreme and other federal courts) branches if the President can simply choose to ignore defending laws he dislikes?

Family Research Council's Senior Fellow Chris Gacek (JD, Virginia) notes that DOMA "affirms the power of each state to make its own decision as to whether it will accept or reject same-sex marriages created in other jurisdictions ... The Defense of Marriage Act preserves the right of the states to govern themselves with respect to family law and domestic relations. DOMA impedes judicial activism regarding marriage and provides needed uniformity in federal law. It is an essential part of preserving traditional marriage in America." In other words, as Quinn Hillyer writes in The American Spectator, "Without DOMA, state and local decision-making would be nil. In fact, the decisions of 49 states could be superseded by the decision of one state to allow such 'marriages'."

The rule of law is essential to the future of representative self-government in the United States. The future of marriage hinges, in large measure, on DOMA. President Obama has succeeded in undermining both this week.