Such is no longer the case. All that matters is the D after their names and the common knowledge that Ds give away more free stuff. Herding DIM voters is like herding sheep. Herding GOP voters is like herding cats.
There's certainly a world of difference between your average Hubert Humphrey supporter and your average Obama supporter. The Democratic Party has basically written off white working and middle class voters completely. For all intents and purposes, it is the official party of the "minority" underclass and a small group of media/legal/entertainment/academic elites who cater to the needs of this underclass.
This transition was partly underway as early as the 1960's, but even 16 years ago Clinton had to pay some lip service to the interest of middle and working class voters. In 2008, Obama completely ignored them, and this will be the MO of the Democrats from now on.