Well, the OP of this debate is whether or not the top 50% get enough indirect benefits from the taxes that they are paying, especially regarding social programs.
Sure, the vast majority of money resides in the top 50%. So, they pay the vast majority of the taxes. You can argue all day long about it being fair. I would disagree with that. But, you will have trouble even making a case that they get indirect benefits from this that equals the amount that they are paying, which is more in line with this debate.
This page has some charts that are a little more current.
They show that individual income taxes are 40% of revenue.
On the outgoing side, it shows that 50% of the budget are direct payments to individuals. This would be medicare, medicaid, social security.
So, if we dropped these social programs entirely, there would be so much money freed up that no one would have to pay income taxes anymore. And, we would have money left over.
Now, you will be quick to point out that this plan wouldn’t be “fair”. The only thing left besides corporate taxes is Social Security (Social Insurance Reciepts = Social Security IIRC) and this would be regressive, burden would fall on the poor, ect.
But, can anybody make a case that the benefits that the top 50% are paying for that they are not using are worth it to them? It’s not. This system is a charity, pure and simple. Someone in that top 5th quintile is paying money that they are never going to recover in benefits.