A growing body of research indicates that the manner in which states govern higher education "matters." Thus, the restructuring of governance patterns may hold important implications for higher education policy, finance, and management. Somewhat more abstractly, shifting governance patterns afford researchers an excellent opportunity to test general theories of government behavior in the specific context of higher education, where such theories have begun to gain in prominence. Not all states have undertaken reforms. Inevitably, therefore, questions arise as to which factors drove certain states to enact changes. Why have states adopted reforms at the times at which they have? To what extent do conventional explanations of policy adoption hold in the case of higher education governance reform? To what extent have shifting governance patterns been driven by economic considerations, political conditions, or problems internal to higher education? To what extent can a single explanation account for the variety of governance changes observed? In this essay, the authors report the results of an empirical analysis that pursued these questions. First, they review the contemporary landscape of public higher education governance and of governance change. They then examine several conventional explanations for governance reform, along with a counter-conventional account--what they call the "political instability hypothesis"--that they believe affords conceptual leverage in understanding policy change. Next, they distill nine hypotheses from literature in the fields of comparative state politics and higher education to guide their investigation. Employing event history analysis, they then test how the demographic, economic, organizational, and political characteristics of states, in concert with policy diffusion pressures among them, influenced the enactment of legislation reforming governance patterns from 1985-2000. In the concluding section, they consider conceptual implications of their work. (Contains 4 tables and 19 endnotes.)