FAQ: The Federalization of the California National Guard — What it Means and Why It's in Court

President Trump sent 4,000 members of the California National Guard to Los Angeles in early

June, saying it was necessary to manage protests and help with immigration enforcement. California’s Governor, Gavin Newsom, responded with a lawsuit, calling the move an overreach of federal power.

The legal showdown has raised questions about who controls the National Guard, when it can be deployed, and what limits exist on using the military within the United States. Here’s what you need to know.

What is the California National Guard, and who controls it?

The California National Guard is part of the state’s organized militia. When under state control, it is commanded by the Governor of California. It can only be federalized—placed under the President's command—under specific legal conditions authorized by Congress.

What's the difference between the National Guard and other branches of the U.S. military?

The National Guard is primarily under state control, unlike the Army, Navy, Air Force, or Marines, which are always under federal command. Each U.S. state (plus D.C. and territories) has its own National Guard. 

While the President can federalize the National Guard in certain situations, this usually requires specific legal authority—often with Congressional approval—and is meant for national defense or large-scale crises. This dual state-federal structure makes the Guard different from other military branches and helps ensure that states retain power over their own military resources in most cases.

Historically, when is the National Guard used?

The National Guard is most often used by state governors during local crises—such as natural disasters, public health emergencies, or civil unrest. For example, governors can call up the Guard to help evacuate communities during wildfires or to assist with crowd control during large protests.

Occasionally, the federal government can deploy the Guard for national missions, but this typically happens only when authorized by Congress or under specific federal laws. Even then, it’s controversial—because the Guard was designed to be a state-run force, not a tool for federal intervention in local matters.

What legal authority did the President rely on to federalize the National Guard?

Trump invoked 10 U.S.C. § 12406, which allows federalization if:

1. There is an invasion or danger of invasion.

2. There is a rebellion or danger of rebellion.

3. The President is unable to enforce U.S. laws with regular forces.

Did the situation in Los Angeles meet those legal requirements?

In short, no:

• There was no invasion or rebellion, only civil unrest—much like what the U.S. has seen many times before.

• State and local law enforcement, including LAPD, were effectively managing the protests and violence.

• The President still had access to all federal law enforcement personnel, meaning he was not “unable” to enforce the law without the Guard.

Was the order issued “through the governor,” as required by law?

No. Section 12406 specifically states that any federalization order must be issued through the governor. The President did not involve Governor Newsom in the process.

Can courts review a President’s decision to federalize the National Guard?

Yes. Although the executive branch claimed the issue was beyond judicial review, courts have consistently held that when a statute limits presidential power, those limits are subject to judicial review.

The court in this case rejected the idea that the President had unchecked authority under Section 12406.

What role does the Posse Comitatus Act play in this situation?

The Posse Comitatus Act (18 U.S.C. § 1385) generally prohibits the use of the U.S. military in civilian law enforcement. While National Guard troops under state authority can assist in law enforcement, when they are federalized, the restrictions apply—unless specifically authorized by Congress.