When you itemize federal taxes, you can deduct up to $10,000 in state taxes (either income or sales, but not both). Since it is difficult to get up to $10,000 in sales taxes but not that difficult to reach $10,000 in income taxes, then most people who itemize will end up paying higher in federal taxes.
How exactly do you end up paying more in federal taxes if you don’t have to also pay state taxes?
When you itemize federal taxes, you can deduct up to $10,000 in state taxes (either income or sales, but not both). Since it is difficult to get up to $10,000 in sales taxes but not that difficult to reach $10,000 in income taxes, then most people who itemize will end up paying higher in federal taxes.