Of all the troubling aspects of the Obama presidency, none is more dangerous than the president's persistent pattern of lawlessness, his willingness to disregard the written law and instead enforce his own policies via executive fiat. On Monday, Mr. Obama acted unilaterally to raise the minimum wage paid by federal contracts, the first of many executive actions the White House promised would be a theme of his State of the Union address Tuesday night.

The president's taste for unilateral action to circumvent Congress should concern every citizen, regardless of party or ideology. The great 18th-century political philosopher Montesquieu observed: "There can be no liberty where the legislative and executive powers are united in the same person, or body of magistrates." America's Founding Fathers took this warning to heart, and we should too.

Rule of law doesn't simply mean that society has laws; dictatorships are often characterized by an abundance of laws. Rather, rule of law means that we are a nation ruled by laws, not men. That no one—and especially not the president—is above the law. For that reason, the U.S. Constitution imposes on every president the express duty to "take Care that the Laws be faithfully executed."

Yet rather than honor this duty, President Obama has openly defied it by repeatedly suspending, delaying and waiving portions of the laws he is charged to enforce. When Mr. Obama disagreed with federal immigration laws, he instructed the Justice Department to cease enforcing the laws. He did the same thing with federal welfare law, drug laws and the federal Defense of Marriage Act.

On many of those policy issues, reasonable minds can disagree. Mr. Obama may be right that some of those laws should be changed. But the typical way to voice that policy disagreement, for the preceding 43 presidents, has been to work with Congress to change the law. If the president cannot persuade Congress, then the next step is to take the case to the American people. As President Reagan put it: "If you can't make them see the light, make them feel the heat" of electoral accountability.