I can not realistically picture them ever paying the debt off or going back to a zero deficit. I bet the most likely endgame will be some kind of future war against The Bad Guys (which they'll make sure to do sufficient propaganda demonization against for the low-brow general public) and then they could use that situation to justify "retiring" (not honoring) the debt. There is historical precedent. And while there are many good and honest human beings working throughout the US gov it would be a naive mistake to think the most important decisions are made by "good" people. History suggests the opposite. In (almost) all countries. Throughout history. And again, ignore words. Any words that come out of a politician's mouth just ignore. Only weigh actions, results and tangibles. Looking at those, the weight of evidence suggests they'll never eliminate the yearly deficit or debt. Just keep increasing it until some huge "oopsie!" reset excuse is found. The kind that will likely involve much loss of blood by the working/labor/non-wealthy classes, world-wide
That's the historical record, reinforced many times over millenia.