I live in GA. From what I can tell, the people that use the libraries here absolutely love them (myself included). Even in this relatively small city, the libraries in this network are fairly well funded and have the more modern awesome stuff going on that proper city libraries have.
That being said, I don't recall a time in the last decade when I was one of more than 4 or so member of the public in there at any time. It sucks. A lot. I guess that my point here is that you're unfortunately likely correct, but those of us that use or need our surprisingly good libraries will fight tooth and nail to keep them as well as maintain the standards they currently have.
The overall concensus in my area is that libraries are great, but nobody uses them, and the asshats in power will (and have before) see that and try to take the systems down for meaningless budget cuts.
If you haven't considered it yourself, see if you can work with the library on a publicity campaign. The library here offers "We [heart] our library" signs for people's lawns. They get people into a city-wide book read every year and give out free copies of the book to whoever wants them. This year, it's The Martian. See what services your library might offer like 3D printing or even just free xeroxing and faxing and see what you can do with informing local social media groups.
My wife is a public library administrator here in Indiana and I would be happy to talk to her about more ideas if you want them.
I know that they have cheap (not free, you pay for materials) 3D printing and the ability to print from anywhere directly to the Library. They even have regular ttrpg sessions held there. I'll see what they have as far as promotional/advicacy stuff goes. I'll contact the library first before I bug you (and indirectly your wife) since they may already have some good stuff set up. Thanks for being willing to help!
No problem, I am very happy to help promote libraries. I think they're one of the country's most vital resources even if lots of people don't take advantage of them.
I thought that was cool so I read the wikipedia page you linked...and that's not what he did.
Carnegie's funds covered only the library buildings themselves, and Carnegie gave library buildings to cities on the condition that the cities stocked and maintained them
He built the buildings but required the cities to pay for the upkeep. We want it the other way around. The libraries already exist but someone has to pay to keep them running.