Marshall sued Bell and the city for violating the Alabama Memorial Preservation Act, which prohibits the "relocation, removal, alteration, or other disturbance of any monument on public property that has been in place for 40 years or more".

[3][8][9] In July 2017, Marshall and others joined an effort led by Texas attorney general Ken Paxton promising legal action if the President Donald Trump administration did not terminate the Deferred Action for Childhood Arrivals (DACA) policy that had been put into place by President Barack Obama.

[12] In 2018, Marshall's opponent, Troy King, accused him of violating campaign finance laws by accepting money from a banned political action committee.

1595), sponsored by U.S. representative Ed Perlmutter (D-Colo.), which would permit marijuana-related businesses in states and territories to use the banking system.

[16] In October 2020, Marshall successfully led a challenge to the Supreme Court of the United States which struck down a federal court-order allowing curbside voting in Alabama as an accommodation for voters worried about contracting COVID-19.

[21] In March 2022, Marshall created controversy by refusing to acknowledge Joe Biden as the "duly elected and lawfully serving" President of the United States during the Senate confirmation hearings on the nomination of Ketanji Brown Jackson to the Supreme Court.

[22][23] In August 2023, Marshall argued that people or groups who assist a woman in leaving the state for purposes of obtaining an abortion could be legally prosecuted.

His office wrote in a court filing that, “[a]n elective abortion performed in Alabama would be a criminal offense; thus, a conspiracy formed in the State to have that same act performed outside the State is illegal.” [24] Following a 2024 ruling from the Alabama Supreme Court that frozen embryos could be considered children, Marshall issued a statement in February that he had no intentions of prosecuting healthcare facilities or families involved with in vitro fertilization.

[27] Prosecutors stated that the explosive contained a "substantial number of nails and other shrapnel to increase its destructive capability".

[31] Marshall leads the Rule of Law Defense Fund, a nonprofit organization active since 2014,[32] which is affiliated with the Republican Attorneys General Association.