Besides the spending spree of nearly every single recent President in history, you mean.
Try not to blame our debt on one person. Doesn't exactly make sense.
We buy too much from foreign countries.
We spend more than we make - on things like defense, foreign aid, education, and other unimportant things.
And whoever 'balances' the Federal Budget is absolutely terrible at it. Though it might be due to the fact that Congress (probably) has to approve of the budget - and they fail at basically everything they do.
So, yeah.
We're fcked. xD