In the 20 months since Mr. Nichols’s death, the state’s Republican leaders have repeatedly maligned Steve Mulroy, the newly elected district attorney for Shelby County, and other Memphis-area officials for failing to address the scope of the city’s crime issues and overstepping their legal boundaries.

At least one police reform ordinance supported by Mr. Nichols’s family, which would have prevented police from stopping cars over more minor traffic infractions, was repealed by Republicans in the legislature.

Mr. Mulroy now faces a threat to oust him from his position when the legislature convenes in January, led by State Senator Brent Taylor. And last month, the top two Republicans in the legislature threatened to withhold sales tax revenue from the city, the second-largest in the state, over plans to put three gun safety initiatives on the November ballot.