Since before the passage of the Affordable Care Act (a.k.a. Obamacare), it became clear that support for the health care plan (both the bill and the law) was destined to be controversial. Whereas Democrats contended that those who knew more about the bill would be more supportive, Republicans suggested that additional knowledge would lead to greater opposition. Looking at these issues in the run up to the 2012 election, we explored what Americans knew about the health care plan, how certain they were that each piece of information they had was correct, and whether they supported or opposed the bill. In work with colleagues at Stanford University, GfK, and the Associated Press, we found that individuals who supported the plan tended to have a better understanding of the contents of the plan than those who opposed it.