Comment by dragonwriter

Existing local income taxes are imposed by local authorities. Because states (unlike the federal government) have general police powers, there generally must be authority for the local agency to do so in state law, but this is not the same as state taxes which are redistributed to local governments (which also exist.) Some states include in their laws allowing local jurisdictions to impose income taxes provisions for collection and distribution to the taxing authority by the state tax agency alongside state income taxes, to avoid the expense of duplicated administrative function, but I don't see how that changes the essential local character of the tax.