By "loudest supporters" - are you referring to the donor class? Money is speech, after all.
The Democratic party has an identity crisis: it's failing to balance special interests and their traditional constituents - post-Goldwater/ southern-strategy. Instead of activating their base, they seem to be courting the political center that has been hollowed out by Maga and polarization, incidentally matching the desires of their donors who abhor any kind of populist leftist politics, including anything in instituted by FDR.