What do you mean when you say that SS is "borrowed from"? Just that they've invested surplus collections in bonds?
(Crash course on US Gov't finance incoming)
How SS was *supposed* to work was everyone makes contributions to SS and the money deposited plus the money earned over time would make the program net neutral.
The problem is that SS monies weren't segregated from the general funds (main budget). So, whenever the government wanted to overspend, they simply took the money from SS and give the SS program US Gov't bonds in return (we'll pay you back later, and take some interest while you're waiting).
So, essentially SS and Medicare/medicaid isn't anywhere near funded.
This is sustainable for a period of time as when you put money in SS you're planning on not taking out that money for a very long time. The problem is that the bill is coming due. Baby boomers are retiring en masse and they don't want to be paid in bonds. They want to be paid in cash so they can pay their bills and live their retirements in some level of comfort.
Compounding this issue is that the estimates for SS were all based upon a lifespan of 65. This figure has been used since the early 1900's. The idea was that when people retired, they would live on average a handful of years. Except now people live a LOT longer, so SS is expected to pay out to these people for multiple decades with ever increasing lifespans. In other words, even if Congress didn't steal all the money from SS, SS would still be effectively insolvent since nobody expected medical science to keep pushing lifespans into the late 70's and 80's.
If you 'forgave' the debt, you would essentially wipe out SS and medicaid/medicare overnight, leaving millions of seniors bereft of their lifetime contributions and living on nothing or virtually nothing. The only way to prevent that would be the raise SS contributions and steal them from the current generation to give to the retiring generation. IE, kick the can down the road again, but this time creating the equivalent on monstrous taxes on the young.
All the talk of managing the debt and deficit is basically stop gap measures to prevent the dam from collapsing. That's why there's talk of it being solvent until XXX year. When that year hits, you're out of cash and you can't pay a dime to anyone.
Long story short, the US debt/deficit is completely FUBAR. Not Trump, Hillary or anyone else is going to fix it.
There's one main reason for this... you will never get enough people with enough political will to actually do what needs to be done to fix it. By 2030 given the current deficit combined with the aging population (retirees who go from contributors to recipients), in order to wipe out the deficit (start paying down the debt), you'd essentially need to cut the US military budget to zero (the bulk of the budget aside from SS/medicaid/medicare) and STILL raise taxes by 50%.
At this point the government is playing "kick the can". They're trying to gradually reduce the deficit (rate of debt growth), and *praying* that the US economy grows fast enough to increase the tax base so that they can keep slowing it down. And hopefully in 40, 50 or 100 years it's big enough that they can actually start paying it down.
Just so you know how screwed up the whole plan is, Canada by comparison has their equivalent of SS (CPP) segregated by law from the general budget. The politicians can't touch a dime. Every contribution that goes in is either held in cash or convertible instruments, with some portion diversified through investments in businesses and real estate so that their retirement funds earn returns.
Interestingly enough, the Canadian retirement system is 100% solvent with no debt and they have the lowest national debt as a percentage of GDP of the G8.
An interesting thing to note here is that if the US SS system had been segregated from the start, the US government would have been forced to either slash their spending and/or raise taxes to maintain a sustainable budget.
I guess that's what happens when you give the grand kids an ATM card to their grandparents' retirement accounts. We shouldn't be surprised if they spend it on waterski's and trips to Vegas.