Kevin Walsh of the University of Richmond School of Law writes:
The twitterverse is alive with tweets about Justice Scalia’s headgear for today’s inauguration. At the risk of putting all the fun speculation to an end . . . The hat is a custom-made replica of the hat depicted in Holbein’s famous portrait of St. Thomas More. It was a gift from the St. Thomas More Society of Richmond, Virginia. We presented it to him in November 2010 as a memento of his participation in our 27th annual Red Mass and dinner.
Wearing the cap of a statesman who defended liberty of church and integrity of Christian conscience to the inauguration of a president whose policies have imperiled both: Make of it what you will.
St. Thomas More was executed for not agreeing that Henry VIII could take over from the pope as the head of the Church of England. I'd say that this was a pretty strong statement from Scalia, to those that have eyes to see.
Related link: Scalia Wears Martyr’s Cap to Inauguration ~ First Thoughts