NEW ORLEANS— A state court here ruled that a developer’s proposed use of hotel tax dollars to pay off the $88.5 million borrowed to build a 653-room hotel at the New Orleans World Trade Center would unconstitutionally take the money from the public schools, the Louisiana Superdome, and the convention center. The Fourth Circuit Court of Appeals ruled 5-0 that the developer’s use of the city’s 13 percent hotel tax on room rentals for its own purposes is “an illegal donation of public money.“ In 2001, a state law was passed creating a special taxing district with the power to use bond money to turn the World Trade Center here into a luxury hotel.