The initiatives are aimed at nullifying the ACA mandate to purchase coverage or face a penalty, but the efforts could make it difficult to enact single-payer health systems should the states choose to do so in the future.
In Florida, voters rejected a constitutional amendment to nullify the mandate by a 51-49 vote. It needed 60 percent of the vote to become an amendment.
Lawmakers in those states put the anti-ACA initiatives on the ballot before the June Supreme Court ruling upholding the constitutionality of the ACA.
"Even before the court decision, they were referring to changes that could not be made by states," Richard Cauchi, health program director at the National Conference of State Legislatures, told MedPage Today.
Prior to Tuesday night's election, 20 states already had enacted either laws or constitutional amendments opposing some specific aspect of the law, Cauchi said -- including Arizona, Ohio, and Oklahoma, which have enacted constitutional amendments.
In other healthcare-related state issues, Florida voters rejected a constitutional amendment that would have prohibited taxpayer funding of abortions, which the state doesn't do anyway. Amendment 6 collected only 44 percent of the vote, but would have needed 60% to pass as an amendment.
The measure, placed on the ballot by a Republican-majority legislature, would also have excluded abortion from privacy rights protected by the state constitution.
Initiatives on Medicaid had mixed results Tuesday night. Louisiana voters supported a constitutional amendment preventing money from the Medicaid Trust Fund for the Elderly from being used for other purposes when the state is eliminating a deficit. However, South Dakota voters rejected a measure to increase the state's sales tax from 4% to 5%, with the additional revenue split between K-12 public education and Medicaid.
Michigan voters rejected a proposal that would have provided financial services for elderly patients to help manage the cost of hiring in-home care workers. It also would have provided training for in-home care workers, and would have created a registry of workers who pass background checks.