What happens when the people paying most of the taxes are not paying enough to cover the direct tax credits that are promised to the people who even now are paying little or nothing?

What will happen when the 40% of the people who pay 95% of income taxes can no longer pay for the checks that the feds (under Obama) will be sending those of the 40% of the people who currently pay ZERO taxes, who will be getting the direct tax credits (not deductions) under Obama's plan?

What will happen when the 5% who pay 60% of the taxes cannot cover Obama's new spending?