Associate Justice Anthony Kennedy was one of four Supreme Court justices to attend Tuesday night's State of the Union address.

Kennedy, a possible swing vote when the court considers Obama's healthcare law, sat along side two of the more liberal members of the court, Justices Ruth Bader Ginsburg, and Elena Kagan. Chief Justice John Roberts was also at the speech. 

The court will be considering the constitutionality of the "individual mandate" in the healthcare law that requires people to buy health insurance. A decision is expected this summer.

Absent from Tuesday's speech were Justice Sonia Sotomayor, who Obama appointed to the court, and Justices Samuel Alito, Clarence Thomas and Antonin Scalia.

At the State of the Union two years ago, Obama irritated some members of the court with a fierce criticism of a court decision on campaign finance reform.