I disagree, the US has been declining since the 1970s. It hit bottom in 2008, and the root factors that caused it are still in play. The financial sector has been unchanged, and it is now even much too big for the government to control, or manage.
For example, one big factor that kept the real estate bubble growing was the artificially low Federal Reserve Board imposed interest rate. Even today that rate is still low. Had the FRB raised the interest rate during 2006-2008 the bubble would have collapsed earlier, and perhaps mitigated the results of 2008.