Congress does have this authority as granted by the general welfare clause.This authority was granted in 1937 when conservatives challenged the constitutionality of the social security act in Helvering v. Davis, 301 U.S. 619 (1937).Please inform yourself. Being a constitutional expert involves a lot more than reading a 6 page document.There are 27 amendments and 200 years worth of supreme court rulings that have molded the constitution to apply to modern times. And as stated above the Helvering v. Davis, 301 U.S. 619 (1937) ruling makes a nationwide healthcare plan 100% constitutional. In order for it to be unconstitutional the supreme court would have to repeal that ruling. And since doing so would end social security, welfare, medicare, medicaid and all other social programs I wouldn't hold my breath.