In oral arguments before the state Supreme Court this week, a number of the justices raised some pointed questions about the constitutionality of the ballot proposal. As approved for the 2018 ballot, the Massachusetts “millionaire tax” would add a 4 percent tax on earnings over $1 million and incorporate that ‘surcharge’ into the state constitution. In addition, the Fair Share Amendment, as it is known, provides that the funds generated by the tax would be used solely for education and transportation. According to the state constitution, unrelated subjects cannot be group into a single ballot question, nor can initiative petitions specify appropriations, a power reserved to the legislature. A host of business group brought a constitutional challenge against the petition after it was approved for the ballot by the Attorney General.