Prosecutors played an important role in the rise of mass incarceration and the perpetuation of racial and ethnic disparities in the criminal legal system in the United States. The progressive prosecution movement emerged as a response to those issues and, although the movement has sparked significant debate, there has been relatively little empirical research examining whether progressive lead prosecutors reduce excess punishment and alleviate disparities. In this dissertation, I partnered with two prosecutors’ offices with progressive lead prosecutors to help fill that gap. Using case processing records obtained from both offices (all adult criminal cases initiated between 2017-2022), I found that prosecutors under progressive lead prosecutors tended to be less punitive in charging and plea-bargaining, but their less punitive approach did not eliminate disparities. While larger plea-discounts under one of the progressive lead prosecutors eliminated the racial disparity in that decision point, disparities in case declination/dismissal, diversion, and felony downgrade decisions remained, even under the more progressive administrations. From interviews with line prosecutors, supervisors, and the lead prosecutors in both jurisdictions (N=43), I found that prosecutors in these offices faced barriers to implementing reform both from within their office, in the form of the principal-agent and mid-level manager problems, and from outside of the office, in the form of resistance from judges, law enforcement, and some segments of the public, as well as a lack of cooperation from defense attorneys. Broadly, my findings highlight the fluid nature of power within courts and the tendency of court communities to seek homoeostasis and minimize reforms, even when those reforms originate from within the court community.