There's US$14 TRILLION in American-owned liquid assets sitting in offshore financial centers for tax avoidance reasons. Change our tax laws to bring that US$14 trillion back (e.g., no more taxes on bank account interest, capital gains and stock dividend payments, a feature of the Steve Forbes flat-rate income tax plan and the FairTax proposal) and the US economy will immediately take off. Also, it means we can start to "wind down" Social Security and Medicare obligations for future generations, since American residents can create financial "nest eggs" for retirement and medical bills completely tax free.
“... the US economy will immediately take off.”
That is IF we do some sensible economic policy thing ... well, that requires a President other than Obama.