It is widely acknowledged that a key cause of the Community Development Block Grant (CDBG)'s longevity is its feedback effect on federal policy making via the creation of a large coalition of beneficiaries. Much less is known about the ''microfoundations'' of this self-perpetuating logic, namely, the city-level mechanisms directing local preferences toward preserving the grant. As a first attempt to fill this gap, this article identifies three such mechanisms and tests them on the cases of Arlington, VA, and Baltimore, MD. The study aims to contribute to a more fine-grained picture of the CDBG's dynamics and suggest new avenues for the reform of this program.