This could be technical or a sign of trouble for the macro economy:

Size of income tax drop surprises U.S. states

June 12 (Reuters) — Personal income tax revenues in April were 15.8 percent, or $7.9 billion, below the same month in 2013, according to preliminary estimates from Rockefeller, a public policy research group at the State University of New York. From January through April income tax collections fell 7.1 percent from the same period in 2013, Rockefeller found. Out of the 38 states for which data is available 33 registered declines. Altogether 41 states collect personal income taxes. “While many states tried to be cautious in their forecasts, early figures indicate that income tax collections are below the forecasts in many states,” Rockefeller found.