Have you heard of neoliberalism - trickle down economics? In the 80's Reagan and Thatcher (UK Prime Minister) decided to adopt a new economic theory; neoliberalism. Prior to this era the US followed Keynesian economics - balanced capitalism.
FDR used Keynesian to get us out of the Great Depression via reducing monopolies' hold on the economy & the markets. He spent heavily on the public via the New Deal. The Acts saved us and led to American prosperity, but this changed in the 80s when Reagan decided to do away with regulation and balanced capitalism.
Thomas Friedman introduced the idea of neoliberalism and deregulation to free up businesses and save them money so the wealth would trickle down to wage earners. This economic ideology created extreme wealth for the wealthy while slowly reducing ours.
We've been on a downward spiral since. Just look at the divide in wealth in the US over 40 years. Globalization is killing the US and the planet via free trade agreements. The reduced labor & environmental rights, etc. have been deregulated since the 80s. Remember when we had unions?
For a great example of deregulation check out the Telecommunications Act of 1996. Clinton deregulated this Act and that's why we have every idiot ever in our media. There are too many deregulations to list since the 80s, but if you look at the New Deal and compare it to now, you'll see what's happened.