Why is the Democratic Party erasing parts of their history?

They are fascists and poverty pimps with the constituents expanding and those to support them less.

Shame may be a reason SSgt Alex Robinson. That is the first one that comes to my mind as a potential reason.

First, a shift in focus is not "erasing parts of their history." The focus is being reduced to the noisier elements of the party, it's going to be interesting to see how that works out for them. My main concern with this is that it may give Democratic politicians more room to support Wall Street over Main Street, so long as their also towing the line on racial and gender issues.