While I 100% agree that red states are the welfare queens of our current system, I don't think it's legitimate to consider that point in this context. The question we have to ask is what is the technocratically correct structure here. If states want to collect tax, that's great, but it shouldn't come at the cost of federal revenue.
> Republicans typically talking about being for smaller [Federal] government should like that the [blue] states are trying to solve the problems most important and local to them via their own means.
There is sort of a reasonable case to be made here, but I think it has major incentive problems. If states were using the revenue they raised to replace federal funds, you might be able to make this case. But as a systemic organizational matter, I don't think i'd want the system to work this way. It's just not a very clean architecture - states are incentivized to levy income taxes more than they otherwise would because it imposes a lower cost on their citizens than other forms of taxes, because of this federal revenue issue. I don't think you want an incentive structure like that.