As explained by Jason Bedrick of the Cato Institute, following precedent from an earlier decision of the U.S. Supreme Court, the New Hampshire Supreme Court has rejected a challenge to the constitutionality of the State's K-12 tuition tax credit program, deciding that, because the law does not directly harm the parties filing the lawsuit, they did not have legal standing to challenge the law.
http://www.cato.org/publications/commentary/turn-court-decision-victory-parents-students-taxpayers