Apathy may be something that grows with time as well. It seems to me (though I don't have much evidence to back it up so I welcome being shown I'm wrong) that a lifespan of a functioning democracy is ~100 years. The people who shed blood for it care. Their children are taught to care as well. But the grand-grand-children, born into a working system, don't have any context of how it was before that would give them motivation to care and perform required maintenance. And then, the system starts to degrade.

And for the US, one could plausibly start that 100 year clock in 1865, rather than in 1789. That would put the start of the apathy in 1965. Feels about right.

(Unless you're going to count it from 1945, in which case the real apathy hasn't started yet.)

We have not yet begun not to care!