Bankruptcy is when an entity cannot service its outstanding debt. All of America's debt is in US Dollars which are produced by the US Government. That means that the US Government can always service its outstanding debt. It may not chose to, but that is debt fraud, not bankruptcy.
Is "buoyant" the word you want to use there? I am not sure what word you wanted to use instead of buoyant.
The US Government is nowhere near bankrupt. There might be a technical bankruptcy, but that would not be a true bankruptcy, and has not happened yet.
There are other horrible things that could happen, like hyperinflation. None of these horrible things have happened. In fact, just the reverse, things have been very good. But there are non-bankruptcy dangers out there.
So far, the independent Fed has done a great job of navigating the threats. I doubt trump will do a better job, if he is able to capture the powers of the Fed.