[9] In January 2024, Attorney General Austin Knudsen challenged the legal sufficiency of the ballot initiative, claiming that the measure "logrolls multiple distinct political choices into a single initiative" and "limits the ability of the state to provide for public health and safety".

[13] Following this ruling, Montana Senate President Jason Ellsworth formed a new special select committee to study judicial oversight and reforms, accusing the Supreme Court of overstepping the separation of powers and alleging multiple other courts of violating the state constitution.

[20][21] In July 2024, MSRR accused the Montana Secretary of State of invalidating the signatures of inactive voters,[22] prompting a legal challenge.

[23] On July 16, Lewis and Clark County District Court judge Mike Menahan ordered the Montana Secretary of State to revert rule changes that led its office to invalidate these signatures and to restore the ones it had rejected.

[27] As of October 2024, pro-amendment groups spent over $11 million on ads supporting Initiative 128, compared to about $105,000 for the referendum's opponents.

[29] Supporters of Initiative 128 argued that the constitutional amendment is necessary to prevent Republican legislators from passing bills to restrict abortion in the state.