Having a relative or two who lives or has lived in the Peoples Republic of Boulder, nothing surprises me... OK -- almost nothing. But just a question... who the heck are these kids' parents (nah... I don't want to know).
Once again, there is no "separation of church and state"... For those not familiar, please read the entire text of the 1st Amendment to the US Constitution:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
It's freedom from a [mandatory] state religion and freedom OF religion if you voluntarily have one... And if you read that as liberally as you can, it means no one may be able to make you say "under God" (such a stretch on the whole state religion tact) but it doesn't mean you should be able to disrupt an entire school because you don't (say it).... and as I understand it, the Colorado law permits a student to participate in the Pledge of Allegiance, but does not mandate students recite...
So just sit there and amuse yourselves... text someone or something... then get over yourselves.