Mike Horton addresses this question on the White Horse Inn blog. Mike frames the issue as follows,
This coming weekend the US will pause to remember those whose lives were lost so tragically in the terrorist attacks of September 11, 2001. Adding fuel to the growing fires of public debate over the role of religion in public life, New York mayor Michael Bloomberg announced his decision not to include prayers for the official event.
Theory is tested in specific cases, and this is one more opportunity to wrestle with a larger question. It’s one thing when a political leader has to choose a clerical representative out of an array of Christian denominations. Today, however, representing the religious diversity of the Republic in public ceremonies is more complicated.
On one hand, this is a constitutional issue. Especially given the history of civil religion in America, it’s implausible to imagine that the nation’s founders ever intended anything like the separation of religion and public life that the mantra “separation of church and state” has come to embody. On the other hand, it is a theological issue. In other words, even if Mayor Bloomberg has no constitutional reason to avoid the liturgical interjections in public commemorations that were included by his predecessor, the debate returns us to a recurring question of decisive importance to Christians. It’s not a question of whether prayer at public occasions of this kind is sanctioned by our Constitution, but, for Christians at least, whether we can participate (much less encourage) such acts of “non-sectarian” worship.
To read the rest of Mike's article, Click Here