The Endorsement Test is Completely Subjective

 Notice how Justice Blackmun interpreted the menorah display, which the Court upheld. This display involved a "memorah...standing next to a Christmas tree and a sign saluting liberty." Would a reasonable observer view this display as an endorsement of religion? 

Justice Blackmun, assuming the role of reasonable observer, says don't worry, it is perfectly copacetic:

 In these circumstances, then, the combination of the tree and the menorah communicates, not a simultaneous endorsement of both the Christian and Jewish faiths, but instead, a secular celebration of Christmas coupled with an acknowledgment of Chanukah as a contemporaneous alternative tradition.

Although the city has used a symbol with religious meaning as its representation of Chanukah, this is not a case in which the city has reasonable alternatives that are less religious in nature. It is difficult to imagine a predominantly secular symbol of Chanukah that the city could place next to its Christmas tree.....

The mayor's sign further diminishes the possibility that the tree and the menorah will be interpreted as a dual endorsement of Christianity and Judaism. The sign states that during the holiday season the city salutes liberty.... Here, the mayor's sign serves to confirm what the context already reveals: that the display of the menorah is not an endorsement of religious faith but simply a recognition of cultural diversity. 

 

Would the average Pittsburgher say to his friends and fellow Steeler fans, "hey, yinz, take a look at that great recognition of cultural diversity over der"? Justices Brennan, Marshall, and Stevens view the Chanukah display as an endorsement of Judaism. The endorsement test is completely subjective, like the art of interior decoration. Everyone has a different opinion of the message conveyed by any particular holiday display.

Now consider Justice Kennedy's dissent:

There is no suggestion here that the government's power to coerce has been used to further the interests of Christianity or Judaism in any way. No one was compelled to observe or participate in any religious ceremony or activity. Neither the city nor the county contributed significant amounts of tax money to serve the cause of one religious faith. The creche and the menorah are purely passive symbols of religious holidays. Passersby who disagree with the message conveyed by these displays are free to ignore them, or even to turn their backs, just as they are free to do when they disagree with any other form of government speech....

Our role is enforcement of a written Constitution. In my view, the principles of the Establishment Clause and our Nation's historic traditions of diversity and pluralism allow communities to make reasonable judgments respecting the accommodation or acknowledgment of holidays with both cultural and religious aspects. No constitutional violation occurs when they do so by displaying a symbol of the holiday's religious origins.