Such a constitutional amendment would be extremely difficult to achieve. This does not address the issues of equity and equality among the counties. Gambling is not a culturally acceptable revenue for libraries at this time. Possibilities do exist but further study is needed. New services could be fee-based but staffing between basic and new services may be an issue.
Liability is an issue.
Marketing would be imperative. The issue is the cost to run versus the return. This could be more appropriate as a Friends of the Library initiative. This is controversial for public libraries because it wouldn't provide equity, may have hidden costs, and increased revenues are uncertain. Opportunities do exist to introduce services which people are not aware libraries can offer.