For more than an hour in front of a packed courtroom, the nine justices heard oral arguments in King v. Burwell, one of the most highly anticipated and potentially consequential cases of this term.

The interplay on Wednesday between the justices and the attorneys representing the Obama administration generally aligned with partisan expectations and covered familiar ground: the meaning and context of a few key words in the statute and what Congress was trying to do when it wrote the law.

The justices spent a great deal of time discussing federalism -- specifically, whether the plaintiffs' reading of the Affordable Care Act would cause inappropriate federal coercion of state governments. Critically, Anthony Kennedy, a conservative justice and possible swing vote, seemed particularly animated about the issue, and repeatedly asked tough questions of Michael Carvin, the plaintiffs' attorney.