Why did the "establishment" accept Keynesianism so readily?

0:00For the first time in the history of economic thought, there have been many differences among economists before that. This is the first time that economists, sort of official economists, professors and writers, etc., actually advocated inflation and deficit spending. Before that, economists almost unanimously advocated balanced budgets, sound money, the gold standard, and so forth. And so, in other words, here we have the Keynesians advocating what governments would love to do anyway, Because before that, economists were sort of like the Peck's bad boy or the doer pessimist in the group. The governments would try to advocate all sorts of wild boomboggles and fancy schemes. The economists would always say, no, it's not going to work. The economists are sort of the official wet blanket among intellectuals and statesmen.

0:50But here we have Keynesians who are not wet blankets. Blanket. They were very exuberant about the idea of government, inflation, deficit spending, and so forth, and so their ideas were adopted with great enthusiasm by the official political establishment.