Why public opinion changes: the implications for health and health policy.

Research on stasis or change in public opinion toward health, health policy, and medical care tends to focus on short-term dynamics and to emphasize the impact of discrete messages communicated by individual speakers in particular situations. This focus on what we term "situational framing," though valuable in some respects, is poorly equipped to assess changes that may occur over the longer term. We focus, instead, on "structural framing" to understand how institutionalized public health and health care policies impact public opinion and behavior over time. Understanding the dynamics of public opinion over time is especially helpful in tracking the political effects of the Patient Protection and Affordable Care Act of 2010 as it moves from the debate over its passage to its implementation and operation.