I still do a few tax returns on the side, and it interests me to see how the tax code affects different situations.
From an actual federal income tax return filed this year:
A family consisting of a husband, wife, and three children, with an income of $70,000. They own a home, so are able to deduct the interest from the mortgage. They also made sizable contributions to charity. Thanks to Bush's tax cuts, they can claim $3500 in exemptions for each person in the household, for a total of $17500.
After their exemptions and deductions, their tax liability was $2899. Since Bush doubled the child tax credit, they get to claim $1000 per child, which lowers that tax liability dollar for dollar. That means they have zero tax liability. And since the child tax credit is refundable, the family not only pays $0 in income tax, but gets $101 from the government.
Now, they had money withheld from their paycheck throughout the year, but they get all of that back too, making their tax return about $1400. It could have been much higher, but, knowing how their return was likely to turn out, I had them withhold the least possible amount from their checks during the year.
This return is similar to that of the "struggling mother earning minimum wage", and that of the family earning $45k, paying zero income tax and getting paid $2400 by the government. Before the Bush tax cuts, that family would have owed $950.