During his presidency and current 2024 candidacy, Donald Trump has chomped at the bit to use the Insurrection Act (actually a series of legal provisions passed from 1792 through 1871) to quell domestic protests he didn’t like and may or may not have included violent elements. However, given that Trump didn’t invoke the act to send the military or National Guard forces to suppress an actual insurrection (defined in the dictionary as a rising in arms or rebellion against an established government) by his own supporters against Congress on January 6, 2021, his future use—or misuse—of the act would likely be selective, should he be re-elected in 2024.

The mob Trump incited to go to the U.S. Capitol actually hoped he would invoke the act, but that he would deputize them to violently prevent Congress from accepting what they falsely believed was a fraudulent election. It is not clear under the law that he could not have deputized them, but the mission would clearly have been illegal. Yet, any future use by Trump of the Insurrection Act to quash mere domestic protests, even violent ones, would not be constitutional unless the state legislature or governor requested federal forces and significant federal laws were being violated.

Article I, Section 8 of the U.S. Constitution gives Congress the power “To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions.” Over time, to carry out this provision, Congress, in the Insurrection Act, has delegated the president (excessively) broad power to deploy the militia (now the federalized National Guard)—and questionably active Army forces—to conduct these functions. However, Article IV, Section 4 of the Constitution states, “The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened) against domestic Violence.”

Thus, unless a future Trump administration was enforcing federal laws when a state wouldn’t (an example would be the desegregation of Southern schools in the 1950s and 1960s) or protecting a state government from invasion or a hostile insurrection, the state legislature or governor would need to request the president send forces for the federal armed intervention to be constitutional. Since the Civil Rights era, no federal armed intervention has occurred without state request.

So, although the Insurrection Act is vaguely worded, too broad, and outdated, it also crucially doesn’t define “insurrection” or “domestic violence” and gives the president too much authority to suppress violence. It is clear from the Constitution that protests, even violent ones, that don’t threaten the enforcement of significant federal laws do not require federal intervention unless the government of the afflicted state requests federal help. State and local police should handle such violence with the help of non-federalized National Guard forces under the state governor’s control if things get out of hand. If events get way out of control, the state legislature or governor can request federal backup to assist civilian authorities in law enforcement. Even the broad Insurrection Act in no case authorizes the president to impose martial law—that is, the substitution of military government for civilian authority. Some Trump advisors with military experience advised him to do this after he lost the election—under what legal authority is unclear.

The reason Section IV, Article 4 calls for state approval of federal intervention in cases of domestic violence was that the Constitution’s framers were wary that the centralized power of a standing federal army was a threat to liberty. This fear of a standing army was also demonstrated later by the Posse Comitatus Act of 1878, which prohibits the U.S. military from involvement in civilian law enforcement unless the Insurrection Act has been invoked. The framers’ vision was that state militias would keep the peace in states and act as a counterweight to the power of any central standing army. Preserving state militias vis-à-vis this centralized power was the original purpose of the Second Amendment, which states, “A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.” In other words, the amendment was designed to prevent the federal government from disarming state militias.

The Insurrection Act is outdated because it was originally passed when police departments were in their infancy and federal law enforcement was virtually non-existent. Since the law’s origin, the capability of state and local police to handle domestic violence independently of the federal government has increased exponentially.

Proposals for a badly needed rewrite of the Insurrection Act need to mirror constraints in the Constitution more closely. Active military forces should not be used for any purpose domestically, and National Guard forces should be federalized only in cases of overseas war, foreign invasion, insurrections against the federal or state governments, and to suppress massive violations of federal law by organized actors. State-controlled National Guard forces, under the direction of a governor, can handle most significant domestic violence that is beyond state and local police capabilities and also respond to natural disasters, etc.

Even when the president uses federalized National Guard forces to suppress large-scale domestic violence at a state’s request, a sunset provision should be written into a revised law: the federal operation automatically ends after so many days unless Congress approves an extension. Also, a complete judicial review of the constitutionality and legality of such executive domestic employment of federalized Guard forces would be an added guardrail. Such safeguards are needed to bulletproof against any future executive overreach at the expense of citizens’ liberties, even if Trump does not return to the presidency.