Harold Pollack has a lengthy article in The Atlantic on what he refers to as "the ticking time bomb" of Social Security disability. It's a more sophisticated article than most. However, Pollack clearly spent a lot of time listening to right wing advocates who are on the payrolls of insurance companies. I don't understand why anyone would think that forcing individuals or their employers to purchase private disability insurance would be a plausible solution for anything. Honestly, I can't understand why the insurance companies think it makes business sense to invest even small amounts of money on a proposition whose adoption is so wildly improbable.
Anyway, here are two interesting graphs from the article.