It is not the only reason. In swing states like Michigan it seems to have been the deciding factor.
https://www.newsweek.com/jill-stein-wins-22-vote-dearborn-gaza-stings-harris-network-1979861
However i doubt that even with a decent campaign of addressing the economic concerns of normal people the Democrats could have hacked it. With the steadfast support for Israel they have shown everyone whose ancestry is somewhere south of the European alps, that they are second grade people, easily dispensable if necessary.
Yeah, how can people not see this? The “American Dream” and times of middle class prosperity were very obviously before China opened its economy and became the new industrial hub of the world. And when off-shoring started, so did real wage stagnation/decline.
Selling the declining American middle class plastic toys did not “make” that class. What made it were stable well paying manufacturing jobs. Trump won’t bring those back with a trade war with China, but the claim that Chinese labor “made” the American middle class is just delusional.