debt as a raw number is, in my opinion, pretty meaningless.  Debt as a % of either assets or sales or earnings is a much more real number to look at.

Not that I think gdp or the value of the government assets are keeping pace with the debt, because I doubt that,  but then on the other hand perhaps they are.  I haven't really looked at the former, and I don't know where you would find the latter.

Hypothetically, if the government were to borrow a trillion dollars and buys Brazil at the SouthAmerican garage sale, did it really put the country in worse shape then if it had kept the debt down?   If the government "saved" money by letting the roads and waterways deteriorate to where they are unservicable, or by replacing our military equipment with some second hand stuff that might work, bought for pennies from the former soviets, would that be good, or would it be bad? 

This all sort of assumes investment.  I don't think much of the current spending classifies as investment.  Social engineering programs seldom produce any value for the money spent.