The US federal government doesn't get its money from anyone, the USD is a sovereign currency. Do you even know what that means? The US federal government is the exclusive issuer of the dollar, hence no one else, unless they have a charter (the banks hold charters) can create officially recognized dollars. Only state and local governments fund themselves with taxes and through the federal government budget. Federal taxes aren't meant to "fund" the US federal government, but rather to maintain the value of the dollar and control inflation, by taking money out of the private sector. Learn monetary policy (how money is created and about the national debt) from a professor:
The Deficit Myth: The Biggest Lie In Politics | 1Dime
US debt is a myth
Now let's get this clear for you, that way you won't make the mistake of falling into this line of argumentation. If the US federal government is able to "print" money at will, does this imply that it has no budgetary constraints or limits and it can just create a 400 trillion dollar yearly budget? No it can't do that, even though it doesn't rely on taxes to fund itself. The budgetary limits of the US federal government are set by our national GDP (Gross Domestic Product), our nation's production capacity. Our level of employment has a lot to do with our GDP, because when people are employed, they're producing products and services, and being paid a wage, which they then use to buy stuff, hence we have an economy. So production and employment is extremely important and determines how much money the federal government can "print" (i.e. how much money the banks can type into a computer keyboard and how much hard cash currency the US treasury can print). So yes, the US federal government has budgetary constraints, but it's not based on how much tax money it receives.
Our state and local governments due rely on taxes to fund themselves and they also depend upon the federal government budget. They receive money from the federal government plus local and state taxes.
As far as your claim about Mao, first I'd like to say. If you want to compare body counts, whose mountain of rotting corpses is taller, you're going to have a really hard time as a defender of capitalism. Capitalist imperialism and colonialism killed more people and continue to do so than the communists ever killed. So you're quite confused if you believe you have the moral high ground upon which to stand and point your finger at communists. You don't. Now with that said, there were many famines in China throughout its history, before there was even one communist. More, the large figure that you gave is bogus and calculated by capitalist propagandists. Scholars like Raymond Lotta, completely debunks your disingenuous claim, showing how it is groundless, without any evidence whatsoever, and a complete exaggeration:
If you want to go this route in our discussion where you start spewing out death tolls, you're not going to do well. Capitalist imperialist hands are drenched in children's blood, so spare me and everyone else your unfounded capitalist figures. More, your Bible is full of divinely condoned death and destruction, and you simply don't care, you justify all of the violence in your "holy book". Whatever your invisible imaginary sky daddy condoned and even ordered is justified, irrespective of its brutality and how many people died. So you're for violence, provided your mythology supports it. It's complete hypocrisy for Bible-believing Christians, whether Protestant or Catholic like you, to be claiming moral high ground when it comes to violence and destruction. Your religion has been incredibly destructive throughout the centuries, so give it a rest and stick to economic arguments, rather than death tolls and mud-slinging when debating communists or Atheists like myself. You religious folks have no moral high ground whatsoever.