Not looking good:
At current estimates, the CBO assumes that tax revenue as a percentage of GDP will equal about 20% in 2015, up from about 15% today. That 5% increase is based almost entirely on the idea that unemployment will fall dramatically. If it doesn't, every 1 percentage point they're off by adds $180 billion a year to deficits. Tack on the same amount for higher unemployment benefits. Bottom line: A crude, back-of-the-envelope calculation shows that if unemployment averages 7% between 2012 and 2021 — instead of the 5.2% currently projected — the budget deficit could be $2 trillion to $4 trillion higher than now envisioned.