You’ll want to read the Editors on the Chief Justice’s folly:
The dissent acknowledges that if an ambiguous law can be read in a way that renders it constitutional, it should be. It distinguishes, though, between construing a law charitably and rewriting it. The latter is what Chief Justice John Roberts has done. If Roberts believes that this tactic avoids damage to the Constitution because it does not stretch the Commerce Clause to justify a mandate, he is mistaken. The Constitution does not give the Court the power to rewrite statutes, and Roberts and his colleagues have therefore done violence to it. If the law has been rendered less constitutionally obnoxious, the Court has rendered itself more so. Chief Justice Roberts cannot justly take pride in this legacy.