The cross, on an outcrop known as Sunrise Rock in the Mojave National Preserve, has been covered in plywood for the past several years following federal court rulings that it violates the U.S. Constitution's First Amendment prohibition against government endorsement of religion.
The justices were to hear arguments Wednesday in a case the court could use to make an important statement about its view of the separation of church and state. The Obama administration is defending the presence of the cross, which court papers describe as being 5 to 8 feet tall.
A former National Park Service employee, represented by the American Civil Liberties Union, sued to have the cross removed or covered after the agency refused to allow erection of a Buddhist memorial nearby. Frank Buono describes himself as a practicing Catholic who has no objection to religious symbols, but he took issue with the government's decision to allow the display of only the Christian symbol.
Easter Sunrise services have been held at the site for decades.
The 9th U.S. Circuit Court of Appeals in San Francisco has repeatedly ruled in Buono's favor. Congress has intervened on behalf of the cross, prohibiting the Park Service from spending money to remove the cross, designating it a national memorial and ultimately transferring the land to private ownership.
The appeals court invalidated the 2004 land transfer, saying that "carving out a tiny parcel of property in the midst of this vast preserve -- like a doughnut hole with the cross atop it -- will do nothing to minimize the impermissible governmental endorsement" of the religious symbol.
Veterans groups are on both sides of the case, with some worrying that other religious symbols that serve as war memorials could be threatened by a ruling in Buono's favor. Jewish and Muslim veterans, by contrast, object that the Mojave cross honors Christian veterans and excludes others.
The administration wants the court to rule that Buono had no right to file his lawsuit because, as a Christian, he suffers no harm from the cross. His main complaint is that others may feel excluded, the government says.
Alternatively, the administration says the land transfer took care of any First Amendment problem.
The case is Salazar v. Buono, 08-472.