If taxation is the art of plucking the most feathers from the goose with the least amount of hissing, my predictions for a social security fix include these.
1. Make 100% of benefits taxable with some short phase in.
2. Increase the maximum social security taxed earnings and institute a third "bend point" at the current limit.
3. Increase FRA by one or two years for people currently under 27. Phase the increase in like the last time.
4. Increase the wage tax rate by something like 0.5%
I think enough people don't understand or don't care enough about these particular things that they will be possible.
If they really wanted to be bold, they could pick a date maybe 35 years in the future and declare that anyone turning 62 after that is eligible only for social security on their own work record, thus eliminating spousal and survivor benefits.