By David B. Rivkin Jr. and Elizabeth Price Foley,

It isn’t enough for Trump to quickly rescind Obama’s executive orders. Congress also needs to act.

The worst legacy of the Obama administration may be disdain for the Constitution’s separation of powers. President Obama’s actions have created dangerous stress fractures in our constitutional architecture, making it imperative that the Trump administration and Republican Congress commence immediate repairs. The Constitution separates power in two ways: among the three branches of the federal government and between the federal government and states. As James Madison wrote in the Federalist Papers, separation creates “a double security” for liberty because “different governments will control each other, at the same time that each will be controlled by itself.” The Obama administration has spurned this core constitutional principle, aggrandizing executive power at the expense of Congress and states. It has rewritten laws, disregarding its constitutional duty to faithfully execute them.

The media and academy enabled the administration’s unconstitutional behavior because they support its policy agenda. But the Framers expected members of Congress to jealously defend congressional power against executive encroachment—even from a president of the same political party. As Madison observed, “Ambition must be made to counteract ambition. The interest of the man must be connected with the constitutional rights of the place.” This principle disappeared during the past eight years. In his 2014 State of the Union address, the president vowed to implement his agenda “wherever and whenever I can” without congressional involvement—to thunderous applause by Democrats.

The Trump administration and GOP Congress should resist the temptation to follow this Constitution-be-damned playbook. The greatest gift Republicans could give Americans is a restored separation of powers. But this cannot be accomplished by merely rescinding the Obama administration’s unconstitutional executive orders. While this is a necessary step, Congress should enact additional reforms. First, Congress can amend the 1996 Congressional Review Act to require affirmative approval of major executive-branch regulations. The law now allows regulations to go into effect automatically if Congress does not disapprove them. The act has been used only once to overturn a regulation because it requires passage of a joint resolution of disapproval—which must be signed by the president. This requirement should be inverted: If Congress does not affirmatively approve a regulation, it never goes into effect. Second, Congress could prohibit “ Chevron deference,” in which federal courts defer to executive branch interpretations of ambiguous statutes. Chevron deference is a judge-made doctrine that has aggrandized executive power, ostensibly to implement Congress’s intent. If Congress denounces such deference, it can simultaneously reduce executive power and encourage itself to legislate with greater specificity. Third, Congress can augment its institutional authority by expanding its contempt power. The criminal contempt statute should require the U.S. attorney to convene a grand jury upon referral by the House or Senate without exercising prosecutorial discretion.

Fourth, Congress can require that all major international commitments be ratified by treaty. A statute defining the proper dividing line between treaties and executive agreements would reassert the Senate’s constitutional role, provide clarification to the judiciary, and encourage communication and negotiation between Congress and the president. Fifth, Congress can enact a law further restricting its ability to coerce states into adopting federal policies or commanding state officials to carry them out. While the courts have ultimate say on the contours of these federalism doctrines, a law could force greater consensus and debate, provide guidelines on Congress’s use of its powers, and signal to the judiciary a reinvigorated commitment to federalism. Restoring separation of powers is necessary and possible. It should be the highest priority of the Trump administration and Congress.

More From The Wall Street Journal (subscription required):