Many millions more people doesn't mean that congress will decide "Oh, we have more cash on hand, let's reduce spending." No, they'll increase spending, because they have more cash on hand.
Say you have a good job (not decent, good), and you get a generous bonus/a larger than expected refund the next year; would you pocket/invest 100% of it, or would you spend at minimum 5% of it?
That's what congress would do with more cash. They would spend it all like drug addicts.
I never suggested a higher total revenue for them to spend. I just suggested a broader application of tax law.
Obviously, I don't agree with your assessment anyway.
Requiring more folks/institutions to pay their share of taxes is meant to change the attitude of voters toward more thrifty candidates - not to change the unchangeable nature of sitting politicians.
Today we have the situation you fear - they spend at will now, completely without regard to how much money comes in each year.
And today more than half the population doesn't care because it's not their money. Even worse, they vote to spend more because it's not their money.