Here's a quote from the article posted above:

"If trickle-down economics worked, then lower tax rates during the Reagan Revolution should have increased the lowest income levels. In fact, the exact opposite has occurred. Income inequality has worsened. Between 1979 and 2005, after-tax household income rose 6% for the bottom fifth of income earners. That sounds great, until you see what happened for the top fifth -- an 80% increase in income. The top 1% saw their income triple. Instead trickling down, it appears that prosperity trickled up!"

What more needs to be said?