The Establishment Clause was added to prevent government from controlling religion, faith, beliefs, etc.  It prevented the Federal Government from establishing a national religion; thereby, ensuring freedom of worship no matter what your beliefs.  Freedom of speech prevents the Federal Government from making laws regarding what we can say on any matter, including religious beliefs.  Saying a prayer does not establish a religion or a church or a set of beliefs.  It is simply one person appealing to a higher power regarding wisdom for that particular group's endeavors.  Who wouldn't want more wisdom in any group?  Denial of prayer is denial of a citizen's rights and/or the rights of the group to decide whether to have a prayer.  The best government, which always seems to be laws and restrictions of one kind or another, is that which is closest to the individual voter.  The Federal Government should stay out of our business, our faith, and our decisions.