Specifically at issue is whether a federal statute that prohibits a person "from re-entering a military installation after a commanding officer has ordered him not to re-enter, may be enforced on a portion of a military installation that is subject to a public roadway easement."
Vandenberg Air Force Base is in a rural area on the coast of central California, about 170 miles northwest of Los Angeles. The base is the site of sensitive missile- and space-launch facilities, and is generally closed to the public.
However, the base is crossed by two state roads that are open to the public.
Highway 1 runs next to Vandenberg's main gate. Near that gate, the base commander has designated an area for public protesting, which though part of the base, also falls within the scope of the Highway 1 easement.
Protester John Dennis Apel has twice been barred from Vandenberg, in 2003 for trespassing and vandalism and in 2007 for trespassing.
But in 2010, Apel entered Vandenberg three times, and each time was escorted off the base. He was convicted of three violations of the federal statute and ordered to pay $305 in fines and fees.
But a federal appeals court ruled in his favor, saying the federal law governing protesters kicked out of a base "applies only to areas over which the federal government exercises an exclusive right of possession."
The federal government then asked the Supreme Court for review.