the Laffer curve is not a straight line.

21st Century Republican tax theory is that all tax increases lead to reduced revenue and all tax cuts enhance revenue.

Also, wasn't Maryland a tax haven? How many of those millionaires were there just for the low taxes? Being a tax haven may be a valid strategy, but you have to stick to it. And it means you aren't a good model for the tax strategies of normal states. Kind of like if K-Mart decided to sell less crappy products and raised their prices, and Target used the resulting drop in sales as an indicator of their own customer-base's price sensitivity.