The book "Obamacare Wars" discusses how the Affordable Care Act (ACA) has been under attack by Republicans since its inception. The focus is on how the federal government and states negotiated the implementation of the ACA, with federalism being the main battleground. The book looks at the creation of insurance exchanges, Medicaid expansion, and regulatory reforms, showing how policy legacies, institutional fragmentation, and public opinion influenced the success or failure of health reform.