1. There's an argument going around, articulated most forcefully by @nytdavidbrooks, that now is not the time for the Democrats to embrace Sanders' social democratic agenda because the economy is growng. 
2. The point Brooks is making is superficially plausible but falls apart when you look at it. The key misunderstanding is the idea that social democracy needs economic downturns in order to gain popularity. But, with one major exception, the reverse is true.
3. The very book Brooks cites in his article makes the opposite point he thinks it does. The whole point of Benjamin Friedman's “The Moral Consequences of Economic Growth,” is growing economies make people not just more tolerant but also more receptive to progressive policies.
4. The Great Depression skews people's memories, but it's important to understand the timing because it lasted so long: the Depression hit in 1929, bottomed out in 1932/33 -- thus doing FDR a favor by totally discrediting Hoover & the GOP.
5. FDR benefitted from the uspwing of 1934-1936 to start on reform. He then self-sabotaged by adopting austerity too soon (creating a mini-recession of 1937-1938). But larger reform agenda flourished again after wartime & post-war booms: the era of mass unionization & GI Bill
6. Aside from complex & special case of New Deal, periods of robust economic growth (early 20th century, 1960s) are the ones where progressive economy policy is most likely to succeed. People feel more secure, see wealth isn't being share & push for it.
7. The great recession of 2008 bottomed out in 2010. We've had 10 years of economic growth. Unemployment is low. Wages haven't kept up. There is an affordability crisis. Now is the best time to push for expanded social democracy since 1960s. More here: thenation.com/article/econom…
8. The above argument centers around Sanders because that was Brooks' target. But it also applies to Warren, who doesn't call herself a social democrat but is offering a nearly equally ambitious program of economic overhaul. It's one I think is sellable, more now than ever.
