President Barack Obama admitted today that his estimate of the budget deficit was off a little, by a mere $2 trillion. According to the Obama administration, the U.S. will run a $9 trillion deficit over the next 10 years — $2 trillion more than it forecasted earlier this year.

Add that to the national debt which is already $11 trillion, and you get a $20 trillion debt by 2019. How much of that will be in the form of government bonds that will be issued to China? Who knows. But, for sure, our grandchildren will be paying for our mistakes.

In its mid-year budget review, the administration admitted that the economy is much worse at this point than it had originally anticipated. Unemployment is way higher than Obama thought it would be, and the economy is still shrinking (though not as badly as it was earlier this year). Because the economy will be bad for years to come, federal tax revenue will be far lower than anticipated. Thus, the deficit will be much greater than Obama originally thought.

From this estimate, it looks like the stimulus package didn’t do a whole lot except make Wall Street bonuses bigger this year.

Obama’s estimates may have to be revised again, as the current estimate expects a quick return to growth in 2010. If we have a double-dip recession or growth is less than expected, the deficit estimates may grow again. Obama was wrong the first time around, so perhaps he will be wrong again.

What does this mean for you? Be prepared for a lost decade.