Under my flat tax scheme, everyone would pay the same % flat Federal income tax with no deductions or write-off's. Then all legal US citizens age 18+ will be given $500/month, regardless of income. So if Jane makes $1 million/year and Bob makes $30,000/year, both will pay the same % in Federal income tax, then receive $500/month from the government.
Bob can be unemployed and still receive $500/month, should he decide to live out of a van and eat $1 burgers, & complain to others that he's a victim of circumstance. Note that the $500 benefit only applies to legal US citizens, not illegals, p. residents, or green card holders.
Each state will retain its power to levy state income tax and use whatever deductions scheme they wish, with the sole exception that the $500/month payment from Feds will not be taxable, nor will it be used to penalize any retirement benefits (SS?).
I'd also consider rolling back community college fees to $5 per unit, and make registering for selective service at age 18 (for both men and women) as a requirement to receive government benefits.