We seldom expect a Supreme Court justice to utter the defining sound-bite on a controversial public issue.  But Chief Justice John Roberts did just that in today’s ruling on President Obama’s healthcare legislation.

Chief Justice Roberts, writing for the majority, described the individual mandate – the legislation’s most controversial element – as a “tax” and noted that the government’s authority to levy taxes is well established.

Describing the mandate as a tax is in sharp contrast with the way the argument was framed in almost every debate: as a question of the government’s power to regulate interstate commerce.  The commerce-clause argument was hard to understand and hard to make convincing.  But everyone understands a tax.

Chief Justice Roberts applied a simple language to a complex and controversial issue, which is the essence of good communication.  By describing the mandate as a tax, Roberts instantly crystallized an issue that had been bogged down in obscure Constitutional arguments and the health benefits of broccoli.  He expressed a complex provision of the law in terms anyone can understand.

Indeed, perhaps if the Obama administration had used this terminology when making its case to the Court there might have been no dissenting votes at all.  (Ok, yes, it would be hard to get Justice Scalia’s vote in any circumstance.)

People can debate Roberts’s strengths as a jurist, but there is no doubt about his skills as a communicator.