JLF’s Roy Cordato writes that while Republicans in the state legislature have jettisoned the leftist approach to social justice in designing the structure of marginal tax rates, they have not completely rejected the idea of building progressivity into the tax system. He explains in this piece:

First, from a philosophical perspective, this approach applies the correct concept of social justice, namely that all taxpayers are treated equally under the law. The standard deduction is available to all taxpayers regardless of income.

But from an economics perspective, it adheres to what doctors call the Hippocratic oath—“first do no harm.” The leftist view of progressivity is not only immoral from a social justice perspective, in that it discriminates against taxpayers simply based on how successful they are as a worker or entrepreneur, it also does damage to the economy.