Introduction: What is public policy?
Public policy as government action is generally the principled guide to action taken by the administrative or executive branches of the state with regard to a class of issues in a manner consistent with law and institutional customs. In general, the foundation is the pertinent national and subnational constitutional law and implementing legislation such as the US Federal code. Further substrates include both judicial interpretations and regulations which are generally authorized by legislation.
Dean G. Kilpatrick, Ph.D. states "Public policy can be generally defined as a system of laws, regulatory measures, courses of action, and funding priorities concerning a given topic promulgated by a governmental entity or its representatives." 
Different forms of citizen participation
The various editors of Wikipedia's entry for Community Organizing  seem to take the point of view that community organizing is the superior form of engaging the state. Be that as it may, they distinguish several classes of participation which they distinguish from community organizing per se.
- Activism: According to Edward Chambers, community organizing is distinguishable from activism if activists engage in social protest without a coherent strategy for building power or for making specific social changes.
- Mobilizing: When people "mobilize" they get together to effect a specific social change, but have no long term plan. When the particular campaign that mobilized them is over, these groups dissolve and durable power is not built.
- Advocacy: Advocates generally speak for others who are unable to represent their own interest due to disability, inherent complexity of the venue such as courts and hospitals, or other factors. Community organizing emphasizes the virtue of trying to get those affected to speak for themselves.
- Social Movements: A broad Social movement often encompasses diverse collections of individual activists, local and national organizations, advocacy groups, multiple and often conflicting spokespersons, and more, held together by relatively common aims but not a common organizational structure. A community organizing group might be part of a “movement.” Movements generally dissolve when the motivating issue(s) are addressed, although organizations created during movements can continue and shift their focuses.
- Legal Action: Lawyers are often quite important to those engaged in social action. The problem comes when a social action strategy is designed primarily around a lawsuit. When lawyers take the center stage, it can push grassroots struggle into the background, short circuiting the development of collective power and capacity. There are examples where community organizing groups and legal strategies have worked together well, however, including the Williams v. California lawsuit over inequality in k-12 education.
Wikipedia also informs us that "Saul Alinsky, based in Chicago, is credited with originating the term community organizer during this time period. Alinsky wrote Reveille for Radicals, published in 1946, and Rules for Radicals, published in 1971. With these books, Alinsky was the first person in America to codify key strategies and aims of community organizing. He also founded the first national community organizing training network, the Industrial Areas Foundation..."