A recent episode of Vox's podcast The Weeds makes a great point that there are far more progressive ways to balance the Social Security budget than to raise the retirement age.
They make the point that compared to the upper class, working class workers in their sixties enjoy their jobs less, and have fewer years to live. That's very true, but I think there's a huge additional reason it's wrong to raise the retirement age: working in your sixties is painful.
I'm 36, and the trend among my friends these days is towards more and more aches and pains. I imagine most of us are going to be experiencing daily pain at 65.
That's bad enough when you're sitting at a desk. But if we were fast food workers? Parking lot attendants? Drivers? It could be impossible to keep working.