Maybe.... or maybe its the person who proposed the idea was a Christian who had support, political connections, etc. and it was agreed upon by the people added those two words that the country was founded on Judeo-Christian principles.....They actually have a legitimate complaint. The pledge is nothing more than a tool of indoctrination. The "Under God" was added because it was an attempt at anti-atheist indoctrination.
And I do not see how it would be "legimate" if its not a legally binding document? How is the supreme court going to rule on something that doesn't necessarily exist in their books?