The White House budget released on Tuesday appears to have double-counted more than $2 trillion in estimated tax revenue. As such, the budget would not balance over 10 years (as promised), even if the U.S. economy were to hit sustained 3% growth (as projected by the White House, but by very few others).
Bottom line: Budget projections are a specious business by their nature, as no one can accurately predict the nation's next decade of economic fortunes. Let alone all of the legislative assumptions required, such as the future of healthcare, the specifics of tax reform, etc. Moreover, White House budget requests have a habit of being ignored by Congress (see: last month). But this double-count is a big unforced error.