The SALT deduction actually keeps their federal tax contribution down because it lowers their federal taxable income.
But not any more. :)
When you make an activity tax deductible, you get more of it. Conversely, when you remove the deduction, you get less of the activity. You will be seeing tax revolts in states where the tax payers are adversely affected by this.
Probably true. And see my post #28 where I discuss how state tax collections will probably go even higher as a result of the federal tax changes. That could trigger the process you’re talking about.
By the way, the reduction of the impact of the property tax and mortgage interest deductions should both work to depress housing prices below what they would otherwise be. As you said, if you remove the deduction you get less of it.