The thing is that the "one nation,
UNDER GOD, with..." part was added in like the '50s or so during the Red Scare/Cold War. To show that the US wasn't a bunch of communists, they added the "Under God" part. Considering we are NOT a nation built "Under God", both that part and the "In God We Trust" on all of our coins is both ridiculous and unconstitutional.
So it is THAT issue that the parent in California had problems with. Not that blind nationalism is a bad thing.
See my previous post, Napoleon. The Constitution of the US prohibits the establishment of religion, as in a national Church such as the Church of England in the UK (still the established religion of the nation). Coins proclaiming trust in God or a Pledge mentioning God are not unconstitutional. The evolution of church / state relations has been gradually away from recognition of Christianity as the only religion in favor of a more inclusive recognition of God (first Judaism was acknowledged, hence the ´Juedo-Christian´ term and more recently Islam. ) Congress opens with prayers, the name of God is frequently invoked by politicians, the US Armed Forces have chaplains. We do not tax religious institutions. These practices reflect the beliefs of most Americans who profess belief in a deity. The nation was founded on principles of religious freedom and tolerance but not on atheism.