US debt has repeatedly overshot official forecasts

U.S. federal debt held by the public has reached roughly 100% of GDP, near levels last seen around World War II.
The concerning part is how consistently the actual debt trajectory has exceeded previous forecasts.
Today's ratio is already around 15 percentage points above the CBO's January 2017 projection for this point in time.
An earlier 2009 forecast projected debt-to-GDP of roughly 42% by 2019. The actual figure reached about 78%.
The CBO now projects the ratio will approach 120% by 2035. If future forecasts undershoot reality again, the eventual debt burden could be significantly higher.
The U.S. fiscal trajectory continues to deteriorate faster than policymakers previously expected.