The Democrats have been so deeply penetrated by the neoliberal/Robert Rubin/Hamilton Project types that they aren’t that different from the right on economic issues. Both want little regulation of banking and open trade and international capital flows. Both want to “reform” Medicare and Social Security. Both are leery of a welfare state, the Republicans openly so, the Rubinite Dems with all sorts of hand wringing and clever schemes to incentivize private companies that generally subsidize what they would have done regardless (note that Americans have had a mixed record in providing good social safety nets, but a big reason is our American exceptionalism means we refuse to copy successful models from abroad).
The powerful influence of moneyed interests on the Democratic party has achieved the fondest aims of the right wing extremists of the 1970s: the party of FDR is now lukewarm at best in its support of the New Deal. Most Democrats are embarrassed to be in the same room with union types. They are often afraid to say that government can play a positive role. They were loath to discuss the costs of income inequality until it became so far advanced that it is now well nigh impossible to reverse it. After all, that sort of discussion might sound like class warfare, and God forbid anyone on the mainstream left risk sound like Marx…
So the Democratic party (and remember, our two party system makes the Democrats the home by default for the left) pretends to be a safe haven for all sorts of out groups: women, gays, Hispanics (on their way to being the dominant group but not there yet), blacks, the poor. But this is stands in stark contradiction to its policies of selling out the middle class to banks and big corporate interests, just on a slower and stealthier basis than the right. So its desperate need to maintain its increasingly phony “be nice to the rainbow coalition” branding places a huge premium on appearances. It thus uses identity politics as a cover for policy betrayals. It can motivate various groups on narrow, specific issues, opening the way for the moneyed faction to get what it wants.