The case is as much about real estate as it is about the right to protest.
Peace activist John Apel has been protesting outside Vandenberg Air Force Base in Santa Barbara County for years. A decade ago, he threw blood at Vandenberg's sign and the base commander banned him from even a designated protest area 200 yards outside the main gate.
But did the commander have the right to do so?
Half a century ago, Vandenberg granted an easement of that piece of property to the state of California, and then to Santa Barbara County, for a public road.
UC Irvine law school dean Erwin Chemerinsky will be arguing the case on behalf of Apel. He says for anyone driving down this particular stretch of Pacific Coast Highway, "You'd have no way to know it was land owned by the federal government."
Chemerinsky will argue that a 1972 case upholds Apel's right to free speech on an open street, even if on military property.
The federal government will argue that military commanders must protect their base from deeper penetration from people like Apel.
Chemerinsky has argued several cases before the Supreme Court, though this is the first time he's done so since becoming the founding dean of UCI's law school. He says the Justices will still address him as Mister, not Dean Chemerinsky.
The case is United States vs. John Dennis Apel.