The IRS previously said these types of programs were fine [1], although in a way intended not to set prescedent. There are a lot of other cases referenced in the memo, some of which probably did set some prescedents. State governments could easily set up targeted funds, if just dropping the money into the general fund is a non-starter.

[1] https://www.irs.gov/pub/irs-prior/p526--2011.pdf