Zelizer calls this the "defining paradox of Obama’s presidency".[475]
The Brookings Institution noted that Obama passed "only one major legislative achievement (Obamacare)—and a fragile one at that—the legacy of Obama’s presidency mainly rests on its tremendous symbolic importance and the fate of a patchwork of executive actions."[476] David W. Wise noted that Obama fell short "in areas many Progressives hold dear", including the continuation of drone strikes, not going after big banks during the Great Recession, and failing to strengthen his coalition before pushing for Obamacare. Wise called Obama's legacy that of "a disappointingly conventional president".[477]
Obama's most significant accomplishment is generally considered to be the Affordable Care Act (ACA), provisions of which went into effect from 2010 to 2020. Many attempts by Senate Republicans to repeal the ACA, including a "skinny repeal", have thus far failed.[478] However, in 2017, the penalty for violating the individual mandate was repealed effective 2019.[479] Together with the Health Care and Education Reconciliation Act amendment, it represents the U.S. healthcare system's most significant regulatory overhaul and expansion of coverage since the passage of Medicare and Medicaid in 1965.