When the United States ratified the 16th Amendment in 1913 allowing a federal income tax, the balance of power shifted from the states to the federal government. The power to tax is the power to dictate.
A prime example of this came in 1973, when Congress, in response to the energy crisis, required the states to lower their maximum speed limits to 55 miles an hour.
As the energy crisis subsided, many states began to oppose the lower speed limit. The federal government simply told the states that they could raise their speed limits if they like, but they wouldn’t be getting any federal highway funds as a result. Every single state decided to take the money.
Years later, 14 states, including Mississippi, have refused to follow the intent of the Affordable Care Act and expand Medicaid. As a result, these states are forgoing billions in federal dollars. Sooner or later, these states are going to realize that the 16th Amendment is a very powerful amendment indeed.