Umm, have you been out of the country for like 3-4 decades?   U.S. economic, fiscal and monetary policy has been dictated largely by the GOP since Reagan.  So how long does trickle-down need to take effect?  50 years?  I'll give you the most hilarious example of your "successful" supply side economics.  I recall about ten years ago reading about a trade group of financial advisers espousing the merits of supply-side economics and it's ability to rev up our economy and create jobs.  Do you know where those same advisers were telling their clients to invest at the same time?  Emerging markets.  I.e., "not America."