Approximately 74 millions people now use Medicaid in the United States, but there is not one Medicaid. A patchwork of policies exist across states, with difference even at the neighborhood level, as Jamila Michener, Government, recounts in her book, "Fragmented Democracy: Medicaid, Federalism, and Unequal Policies."

Read more about Jamila Michener's research: Why Are Lower-Income Americans Apolitical?