Food stamps - more benignly known as SNAP (Supplemental Nutritional Assistance Program) - make up a huge share of the US government's welfare bill. It only ever seems to grow (though has steadied in recent years.) The Daily Signal
explains why and what Trump is proposing:
The food stamp program is 92 percent funded by Washington. Washington sends blank checks to state capitals—the more people a state enrolls in food stamps, the more money Washington hands out.
A dirty secret in American politics is that many governors, both Republican and Democrat, regard this type of “free money” poured from Washington as a benign Keynesian stimulus to their local economies. The more spending, the better.
The Trump budget recognizes that the food stamp program will become more efficient if the state governments that operate the program have “skin in the game.” Therefore, it raises the required state contribution to food stamps incrementally from 8 percent to 25 percent.