Randy Barnett, lawyer and professor of constitutional law and contracts at Georgetown University Law Center, says the rewriting of the Patient Protection and Affordable Care Act (ACA or Obamacare) to make the individual mandate a tax rather than commerce clause regulation did not damage and may have advanced the case for narrowing the commerce clause.
Today, the Roberts Court reaffirmed the "first principle" announced by Chief Justice Rehnquist some 17 years ago in Lopez: the federal government is one of limited and enumerated powers. It accepted all of our arguments about why the individual insurance mandate exceeded the commerce power: "The individual mandate cannot be upheld as an exercise of Congress's power under the Commerce Clause," wrote Chief Justice Roberts. "That Clause authorizes Congress to regulate interstate commerce, not to order individuals to engage in it." Then the Court went farther to invalidate the withholding of existing Medicaid funding as coercive, thereby finding an enforceable limit on the Spending Power.
In the 1930s & 40s, when Congress was asserting new powers to address the grave distress caused by the Great Depression, the Court relented and allowed it to reach wholly intrastate activity that, in the aggregate had a substantial affect on interstate commerce. This was interpreted by academics to mean that Congress now had a plenary power over anything that affected the national economy, which means any activity at all. The Court would always defer to Congress's assertion of its Commerce Clause powers.
I defer to Barnett's deep understanding, though my gut tells me bad rulings make bad law, and this one seems to read so tortured that even the concurrers (concurrors?) don't like it. (I admit I haven't finished reading it.)