> I don't see why people would be against SALT deductions. When the Federal government allows you to deduct certain line items from your taxable income, it's

> I don't see why people would be against SALT deductions. When the Federal government allows you to deduct certain line items from your taxable income, it's usually as an incentive for that thing (eg charitable donations deduction). It's really debatable if we really want to be incentivizing higher state taxes. While taxation is an important way to pay for necessary services, you need some downward pressure on it (just like prices) that ensures that we're spending every dollar as efficiently as possible. If you have a more federalized tax structure where you pay more in state taxes than Federal taxes, you probably don't even need this kind of affirmative incentive anyway. > If government wants to incentivize some activity, then they should just pay for it. Agreed, and that's essentially what critics of the SALT deduction call it: the Federal government paying for, and as a result incentivizing states to increase their taxes.