(Charles Rex Arbogast/AP)

The battle was joined, Loop Fans may recall, in late June, when conservative jurist and appellate Judge Richard Posner sharply criticized Scalia, saying his dissent in the Supreme Court’s ruling in the Arizona immigration case was political.

“It wouldn’t surprise me if Justice Scalia’s opinion were quoted in campaign ads,” Posner wrote in Slate, adding that part of the opinion had the “air of a campaign speech.”

Scalia was asked about this on Fox News Sunday, where he appeared to promote his new book “Reading Law: The Interpretation of Legal Texts.”

“He is a court of appeals judge, isn’t he?” Scalia asked. (Ouch.)

Scalia and Posner were faculty colleagues at the University of Chicago law school. In fact, in his book, Scalia cites at length a passage from a Posner text, and concludes: “The analogy limps.” (‘mongst the legal scholars, this is considered a devastating shot.)

When assured that Posner was, indeed, an appeals judge, Scalia said, “He doesn’t sit in judgment of my opinions as far as I’m concerned.”

“You sit in judgment of his opinions?” host Chris Wallace asked.

“That’s what happens,” Scalia replied.

“And people wonder why you push people’s buttons every once in a while,” Wallace said.

“It’s fun to push the buttons,” Scalia said. “When Richard Posner comes out with a statement like that, I should fire back a statement equally provocative.”

Does that mean it wasn’t political?

Here’s the clip (skip ahead to about minute 18:33).