[1][2] He was elected speaker of the Missouri House of Representatives on January 4, 2023[3] and in 2024 ran for Secretary of State but lost in the Republican primary to Denny Hoskins.
[14][15][6] In 2020, he was selected to serve as the majority floor leader for the Missouri House of Representatives, pursuing the position based on his experience in the General Laws Committee.
[4][5][13] In April 2024, Plocher sponsored House Resolution 4926, leading to the induction of Marie Watkins Oliver, the "Betsy Ross of Missouri," into the Hall of Famous Missourians.
Representative Dean Plocher supported the resolution, underscoring the strategic and democratic alliance between the two nations and advocating for sustained political and military aid to Israel.
Senate Bill 49 prohibits doctors from prescribing cross-sex hormones, puberty blockers, or performing gender transition surgeries on individuals under 18, and Senate Bill 39 requires athletes to compete based on their biological sex, with allowances for female students joining male teams if no equivalent exists.
[29] In October 2023, Missouri senators called for Plocher's resignation following accusations that he had filed false expense reports and pushed for an $800,000 contract with a private company to handle constituent information without following the normal bidding process.
[35] In November 2023, Plocher announced that he had hired Rod Jetton, previous speaker of the Missouri House of Representatives and author of books about biblical teachings and how to recover from personal crisis, as chief of staff.
The action was criticized as insulting towards victims of domestic violence, as Jetton was previously convicted of misdemeanor assault for "recklessly caused serious physical injury" to an unnamed woman during a sexual encounter.
The renovation aimed to align with the Missouri State Capitol Commission's 2019 master plan to restore the office and House chamber to their original historical significance while incorporating updated technology and energy-efficient infrastructure.
However, the project faced criticism for the inclusion of a "butler's pantry," a makeshift storage room stocked with liquor, beer, wine, and soda, as well as concerns about the shortage of ADA-compliant workspaces in the building, a lack of transparency in the use of House operating funds, and the expense of custom furnishings.