By DAVID B. RIVKIN JR. And LEE A. CASEY, Feb. 2, 2015 7:40 p.m. ET

A very public dispute broke out last week when Nevada Attorney General Adam Laxalt went against Gov. Brian Sandoval’s wishes and joined a lawsuit filed by 25 other states challenging President Obama’s imposition of his immigration reform policies by executive action.

Messrs. Sandoval and Laxalt are both Republicans who agree that the current immigration system is broken and that comprehensive reform is necessary. But Mr. Sandoval opposes litigation and has suggested that new immigration reform legislation is the best way to proceed.

Yet on Jan. 26 Mr. Laxalt announced that Nevada had joined the plaintiff states in Texas v. United States of America. “As Nevada’s chief legal officer,” he explained, “I am directed by Nevada’s Constitution and laws to take legal action whenever necessary ‘to protect and secure the interest of the state.’ ”

Mr. Laxalt was right to join the suit. Mr. Sandoval’s legislative path will neither solve America’s vexing immigration problems nor rein in a president who has ignored the Constitution’s limits on executive power.

Texas v. United States of America challenges the president’s use of an executive order to suspend federal immigration laws that require, among other things, deportation of undocumented immigrants and strict limits on who may lawfully work in the U.S. The Constitution requires that the president “Take care that the laws be faithfully executed,” and provides no exemption for laws with which the president disagrees.

As the Supreme Court stated in Youngstown Sheet & Tube Co. v. Sawyer (1952), ruling against President Harry Truman’s seizure of the nation’s steel industry during the Korean War, “the President’s power to see that the laws are faithfully executed refutes the idea that he is to be a lawmaker.”

The president is, in other words, stuck with laws passed by Congress and signed into law by previous presidents. The reason for this is at the heart of America’s constitutional separation of powers—the power to make laws and to execute them are divided between separate branches of government, Congress and the president respectively.

The third branch—the judiciary—has the power to say what the law is, including when the president and or Congress have crossed the constitutional lines. It is only litigation before the courts that can now vindicate the most basic tenets of our constitutional system.

However desirable immigration reform might be, congressional action won’t prevent this president from ignoring provisions in a new law that he dislikes or opposes. Only a determination by the courts that he has overstepped his constitutional authority can do that. Unless the president’s ability to play lawmaker is decisively defeated in litigation, congressional legislation on any contentious public-policy issue would be inherently futile.

Nor is Mr. Laxalt obliged to follow Gov. Sandoval’s preference. Nevada law permits the governor to direct the attorney general to bring or defend an action in the courts. But as Mr. Laxalt explained, it also imposes an entirely independent obligation on the attorney general to take such action if he believes it necessary to secure the state’s interests.

All American states, including Nevada, have critical interests at stake here, both because of the burdens President Obama’s suspension of federal immigration law imposes on their state budgets and governments, but also because of their basic character as coequal sovereigns. The Constitution is a “grand bargain” among the states and the American people. That bargain includes a powerful federal government, but one that has limited powers that may be exercised only in accordance with the institutional arrangements the Constitution creates.

The separation of legislative and executive authority is among the most important limitations on federal power. It is now up to the federal courts to restore the Constitution’s balance between the president and Congress and between the federal government and the states. Mr. Laxalt made the right choice. Those state attorneys general that have yet to join Texas v. United States of America should follow his lead.

Messrs. Rivkin and Casey practice law in Washington, D.C., and served in the White House and Justice Department during the Ronald Reagan and George H.W. Bush administrations.

Source: http://www.wsj.com/articles/david-rivkin-and-lee-casey-nevadas-right-choice-on-immigration-1422924012