Let's start with that 39.6% top marginal rate. He has told us over and over that it is the rich who need to pay more, yes? Has he ever once suggested that the 50% of Americans who are paying little or nothing into the federal treasury need to pay more?
I'm not sure if this has been pointed out in the thread yet, but those 50% of the people don't pay income taxes because they don't make enough to be taxed. They DO however pay payroll tax and use taxes like sales and gas taxes. So that is one of the most insulting and stupid rhetoric points that the Right Wing has, by the way.
If by payroll tax you are referring to SS, then that is not the same thing as a tax. That money is ostensibly reserved to pay the individual's SS retirement. Additionally, employers match that contribution, adding to each individual account.
Sales taxes are usually local taxes and do not go into federal coffers. Any other taxes, like the federal tax on fuels, etc, can accurately be described as "little or nothing" when compared to the amount paid as income taxes.
When you take into account the amount paid to that 50% in the form of EIC and various other income tax rebates, they often not only do not contribute to the tax base, they are paid funds in excess of any additional taxes levied by states or municipalities.