You guys over-simplify.
The foundational principle of the Democratic party, which admittedly leans a bit too far left, is to ensure support and minimal human services for those who cannot afford them or who could not otherwise get them yet desperately need them.
In principle, this foundational tenet is right and good. However, politicians are exactly like leeches, living off the blood and work and life of their constituencies. They bloat and gorge themselves on others and the democratic party has long since strayed from the proper path of providing reasonable care for people with mental disabilities, funding of medical research for disease. The funding of successful improvements in universal education in this country, the care and provisioning of the Social Security program that so many Americans have supported throughout their lifetimes. These are the "social" programs that the Democratic party should truly focus their energies on. However, they have chosen instead to focus on more and more radical programs and policies that actually drain our national resources, both hard and financial, continue to exacerbate our class-separation problem (which coincidentally helps Democrats retain power and continue to become more wealthy and influential politically), and honestly their new policies ultimately produce very little in terms of results.
The party has strayed too far from it's actual purpose and value. They've become too radical in an effort to build more power and draw more followers. Along the way they've actually alienated a large part of their core, but they've also managed to woo a young generation of future voters with what are very likely empty promises. While the short term rewards from this millennial generation may result in some election victories, when the democrats continue to fail to produce the pipe-dreams of success and unity that they attempt to sell, they will quickly disenfranchise the petulant millennial masses and they'll find themselves in even more dire straits than they are in now.
The democrats MUST work their way back to what they are supposed to be, mild social reformists who's primary agenda is the preservation of the middle class. Because we are LOSING the middle class. I'm not convinced the republicans truly give two ***** about that either, but they are at least saying the right things and doing the right things to convince the American people that there is an attempt to secure jobs and preserve some semblance of the American Middle Class. The democrats have totally bailed on that and they've gone all in on minorities and gimmicks.