The complaint is that by reducing taxes for highest incomes there are fewer resources for the state to address the wellbeing of its citizens. It is not that the poorest pay less tax, it is whether social services and other government programs like education, environment, etc. are cut as a consequence of lower taxes on the rich (note the difference from raising taxes - where the wealthiest have greater capital mobility and access to professional services to shield incomes from taxation, so increasing taxes can fail to raise anticipated revenues when things go the other way.)