Many things that this graph shows.

1.) FDR/Truman progressive "New Deal" policies gave the U.S. the highest economic growth it ever saw. No Republican or Democrat "neoliberal" or otherwise ever comes close.

2.) The economy under Republicans generally tends to fall during their second terms (if they get one). Furthermore, the growth that they experience in their first terms is also generally dwarfed by their Democrat successor in their first term.

3.) Democrats generally do better on the economy in their second term (if they get one). There is no fall-off.

4.) The economic growth observed under Democrat administrations during the "neoliberal" era is most likely less due to deregulation and more due to raising taxes on the wealthy and investing in social services.

During the FDR/Truman era, taxes on the wealthy were very high, and the investing in social services/protections for workers was also very high. The economy had very high levels of growth.

While there was growth in the Clinton/Obama eras, there possibly could have been more if they were even more progressive.

In fact, some argue that Bill Clinton's deregulations (championed by right-wing economists and hated by progressive "New Deal"'ers) directly helped facilitate the recession of '07-'09 (which itself occured under Bush's second term mismanagement).

Tl;Dr: Keynes was right.

Keyenes also was bi and liked people on the younger side. Wow! Pedos getting tired of winning here...