title: Interest Group Conflict Over Medicaid Expansion: The Surprising Impact of Public Advocates.
abstract: OBJECTIVE
  We examined the potential economic, policy, and political influences on the decisions of the 50 US states to expand Medicaid under the Affordable Care Act.
  
  
  METHODS
  We related a measure of relative state progress toward Medicaid expansion updated to 2015 to each state's economic circumstances, established policy frameworks in states, partisan control of state government, and lobbyists for businesses, medical professionals, unions, and public interest organizations.
  
  
  RESULTS
  The 9201 lobbyists working on health care reform in state capitols exerted a strong and significant impact on Medicaid expansion. Controlling for confounding factors (including partisanship and existing policy frameworks), we found that business and professional lobbyists exerted a negative effect on state Medicaid expansion and, unexpectedly, that public interest advocates exerted a positive effect.
  
  
  CONCLUSIONS
  There are 3.1 million adults who lack coverage because they live in the 20 states that refused to expand Medicaid. Although political party and lobbyists for private interests present significant barriers in these states, legislative lobbying on behalf of the uninsured appears likely to be effective.
authors.affiliation: Timothy Callaghan is a PhD candidate in the Department of Political Science, University of Minnesota, Minneapolis. Lawrence R. Jacobs is with the Humphrey School of Public Affairs, University of Minnesota.
authors.forename: Timothy
authors.initials: T
authors.lastname: Callaghan
authors.affiliation: Timothy Callaghan is a PhD candidate in the Department of Political Science, University of Minnesota, Minneapolis. Lawrence R. Jacobs is with the Humphrey School of Public Affairs, University of Minnesota.
authors.forename: Lawrence R
authors.initials: LR
authors.lastname: Jacobs
mesh_terms: D000328:Adult; D016265:Conflict of Interest; D003254:Consumer Advocacy; D006801:Humans; D007348:Insurance, Health / Q000191:economics / Q000331:legislation & jurisprudence; D008119:Lobbying; D008484:Medicaid / Q000191:economics / Q000331:legislation & jurisprudence*; D058991:Patient Protection and Affordable Care Act / Q000191:economics; D011057:Politics; D013219:State Government; D014481:United States