Definitely each State has set its own requirements for income for qualifying for WIC since they're responsible for using the federal monies. Sometimes it's supplimented with a small revenue from the State since its considered a program vital to monitoring children's health in those years before anyone else ever sees them. But some States have made it very difficult to qualify.
When I became pregnant overseas, we qualified for WIC support for the first year with dh as a Tsgt. As soon as Jan rolled around with a 3% payraise, we made $18 too much to qualify for it. Not really a biggie since I didn't ff, but being able to get expensive Lactose-free milk that I drink, the nice eggs, & cereals certainly helped the budget. I didn't like all the juice that was authorized and rarely ever purchased them. There were other items on the 'cheques', but I didn't use those either.
When I moved to TX, I was amazed to find out from a mother that her family did not qualify for WIC benefits with 3+ members-- the husband was a Staff sgt, she didn't work, they had a 2 year old daughter, and she was pregnant -- so that counts as 4. It didn't matter whether or not they lived on base, they made 'too much money' even though they had no debts and were living paycheck to paycheck. And that's really difficult to believe since it's been just as expensive to live here as overseas.
I do think WIC has played a part with children's obesity & teeth problems with all the juice that has been supplied to the families. Empty sugar calories that (despite reccomendations) many families just give their young children all they want
jmho