Montana deepfake election law blocked as likely unconstitutional

A federal judge in Montana ruled that a state law targeting AI deepfakes in political speech is likely unconstitutional because it amounts to viewpoint-based discrimination, blocking the state from enforcing it against a conservative group challenging the statute.

U.S. District Judge Susan P. Watters issued a preliminary injunction on Wednesday, September 17, 2026, in U.S. District Court in Billings, Montana. The ruling prevents the state and the Montana Commissioner of Political Practices from investigating or prosecuting Dan Bartel, identified as a former Republican state lawmaker, and his group Accountability in State Government, a conservative PAC, for violations of the law.

The Law and the Challenge

Montana's statute was designed to restrict AI-generated advertisements in election speech that could injure a candidate's or party's reputation. However, the law's structure created a constitutional problem: it allowed AI-generated ads intended to "bolster a candidate's reputation" while barring deepfakes designed to "injure the reputation of a candidate or party."

Bartel's group sued after the state began investigating them under the law. The constitutional challenge centered on whether the statute violated the First Amendment by discriminating based on the political viewpoint expressed in the ad—permitting pro-candidate AI content while blocking anti-candidate AI content.

First Amendment Violation Found

Judge Watters agreed, finding the law likely violated the First Amendment because it amounted to viewpoint-based discrimination. Speech restrictions that turn on whether a message supports or opposes a candidate face strict scrutiny under constitutional law, and the judge concluded Montana's statute could not survive that test.

The injunction applies specifically to the named plaintiffs—Bartel and his group—and does not block statewide enforcement of the law against other parties. This means the statute remains on the books and could still be enforced against other entities, though the constitutional ruling suggests future enforcement may face similar legal challenges.

Implications for AI Regulation

The decision highlights the tension between election security and free speech. While states and the federal government have sought to regulate malicious deepfakes in political advertising, any restriction that distinguishes between AI-generated content based on its reputational effect—rather than on provable falsity or deception alone—may encounter First Amendment obstacles.

The ruling does not determine the constitutionality of the law on final review; it addresses only whether the plaintiffs are likely to succeed on their First Amendment claim, a necessary threshold for a preliminary injunction. The case may proceed to trial, where the ultimate fate of Montana's deepfake law will be decided according to Reuters.