A 10-year-old boy is taking a stand for “liberty and justice for all,” refusing to say the Pledge of Allegiance until gays and lesbians enjoy equal rights. Good for him. But this will be best achieved by getting the state out of marriage entirely. Let people define marriage how they will. Barring that, the second best option so long as the state monopolizes the definition and the legal system is to insist that the state has no right to limit marriage to opposite-sex unions, thus denying homosexuals equal legal rights, tax benefits, etc., within its auspices.
The state can never bring “liberty and justice for all” so it is incoherent, though a good rhetorical device, to make one’s pledging allegiance to it contingent on its doing so. Pledging allegiance is itself morally suspect insofar as it carries connotations of feudalism, and morally bankrupt insofar as allegiance is pledged to the state. I think it is no accident that the Pledge was not created until after the Civil War, in 1892, roughly a hundred years after the signing of the Constitution and not long before the US government’s first overseas imperial war. Nor that its creator, Francis Bellamy, was a statist-socialist intent on promoting nationalism in public indoctrination camps schools. (Incidentally, as an aside, the phrase “under God” wasn’t added to the Pledge until 1954, and “in God we trust” wasn’t the official US motto until 1956.)