Legislators of many states believe it is best to give in to wealthy residents, before those residents move to greener pastures with lower taxes.
Delaware has given in to the common fears of many states and repealed its estate tax, according to Forbes in "Latest State To Repeal Estate Tax: Delaware."
Delaware's estate tax had not been in existence for very long. It was only passed in 2009, when the state faced a temporary revenue shortfall and it was believed that the estate tax could help make up for it.
However, the tax itself brought in a relatively small amount of money. Attorneys representing wealthy people who had left the state, also informed officials that a primary reason for doing so was the estate tax.
As a result, it was believed that the tax was costing the state more in lost income tax revenue than it gained in estate tax revenue.
Only a minority of states still have an estate tax.
Reference: Forbes (July 5, 2017) "Latest State To Repeal Estate Tax: Delaware."