Jon Hacker is a familiar face in the Supreme Court chamber, everywhere except at the lectern.

The O’Melveny & Myers D.C. partner is co-director of the Harvard Law School Supreme Court and Appellate Advocacy Clinic. He also co-chairs the committee of the National Association of Criminal Defense Lawyers that writes amicus briefs in Supreme Court criminal cases. In both capacities, he is often in the Supreme Court bar section watching oral arguments. He has also been “second chair” in numerous Supreme Court arguments.

But he has never had the chance to stand up and argue a case before the nine justices — until next Monday Jan. 10, when he will argue for the in Matrixx Initiatives v. Siracusano, the so-called “Zicam case.”