The California Endowment--"a private foundation committed to the expansion of affordable, quality health care for all Californians, with an emphasis on providing health care to underserved and low income communities"--has filed a cert-stage amicus curiae brief in HHS v. Florida (No. 11-398). The brief is authored by constitutional law professor (and former Stanford Law School dean) Kathleen Sullivan. In essence, it argues that the minimum coverage provision is a proper exercise of Congress's commerce power because (a) an individual's uninsured status provides a "tangible link" to commerce, and (b) the provision of uncompensated care substantially affects interstate commerce. The brief also argues that the individual mandate is an essential aspect of a broader regulatory scheme, which scheme plainly regulates interstate commerce.
You can access the brief here.