I think the economy is in a deep recession and really none of the candidates can fix this problem easily. There both internal and external factors at work, and tax policies alone will not fix the economic recession that quickly.
Nonetheless, it seems that Sen Barrack's tax policy of increasing the tax rate for highly compensated taxpayers and corporation is a techncally flawed policy. This tax policy will worsen the recession and will result in a pro-longed recession.
Sen McCain is proposing increasing the tax cuts to both middle class and corporations that will increase the budget deficit, leading to higher inflation in the long run!
All in all, it seems Sen McCain's tax policy will help US taxpayers in the short run, will has a greater possibility of boosting the economy. Hence, I support Sen McCain's tax policy. reluctantly.