When it's declared an unconstitutional income tax and the state is ordered to refund taxpayers, where are the funds going to come from? We're not going to claw them back from schools, right? The resulting deficit is going to suck. I wish we had gone straight for a constitutional amendment that made this tax legal, rather than jumping through "it's not an income tax, it's an excise tax" logic hoops.
Maybe I'm wrong and this will stand up to scrutiny. It's certainly done so for longer than I initially expected.