The Federal Government funds >90% of California's medicaid expansion which is the vast majority of newly-insured people under the ACA. 1 in 3 Californians now receives free health care under Medi-Cal, California's medicaid program. If the Feds withdrew medicaid expansion funding I don't think California could afford to keep it up themselves without extremely painful tax hikes (which it may already be slating for future pension bailouts).