> If your intent of to artificially promote low tax and spending at the state level, yes, if you want the federal government to be neutral on state policy the c

> If your intent of to artificially promote low tax and spending at the state level, yes, if you want the federal government to be neutral on state policy the correct way is full deductibility. This seems like a very odd definition of 'artificial'. The federal government says "we want 30% of your income". Why exactly should the state be able to pre-empt that? > More accurately, under the old system states could tax as necessary to support the spending policy which create the environment in which people in the state are able to earn income without the federal government artificially disincentivizes policy that produces better net results if it happens to require higher taxes. (And, because it didn't even abandon deductibility but limited it to a fixed dollar amount per taxpayer, artificially discourages policy not just by the level of taxation, but the distribution, on top of artificially punishing states for a high local cost of living, where if they tax the same share of the same real—based on local costs—income as a lower CoL state will see more money taken by the feds.) You keep using this word 'artificial', but I don't see much justification for it. I also don't see much evidence for "better net results", nor do I think that's even relevant here. If the states want to levy taxes, they should. But I see no serious argument put forward here for why those taxes should come at the expense of federal taxes.