If you want to understand where Obamacare stands to have the most significant impact, check out these new maps from the Census. They show uninsured levels for every county in the United States, broken down by income level. The top map shows the population that is likely to qualify for Medicaid coverage, if they live in a state that is expanding that program. The bottom map captures the Medicaid-eligible population and those who may qualify for subsidies to purchase health insurance in the new marketplaces.There are two things that these maps tell me. First, they underscore the significant impact that state policy will have on the Affordable Care Act. Texas and Florida have both decided not to participate in the Medicaid expansion, concerned about the financial implications of expanding an entitlement program. Those are states that tend to have a higher uninsured rate that will see them dip less than was initially expected under the health law.Second, these maps explain why you see a group like Enroll America focusing its work on 10 states, rather than sweeping out across the country. There are some areas of the United States, like the upper Midwest and the Northeast, that already have a relatively low uninsured rate. That likely explains why you see national groups focusing on a smaller area where they can likely have a larger impact, the places where uninsured rates for the poor hover as high as 40 percent."