>the same income should pay the same federal tax. Given the vast difference between local economies, this would result in huge disparities in effective tax rat

>the same income should pay the same federal tax. Given the vast difference between local economies, this would result in huge disparities in effective tax rate depending on where you live. For example, a person who makes $100k in Kansas City, MO is far wealthier than someone making that much in San Jose, CA. Taxing them at the same rate is essentially a massive tax break for one and not the other. The SALT deductions account for this.