Ramsin Canon at the Gaper's Block blog Mechanics aruges that we really don't have a good idea of what constitutes a 'good' Democrat, and this lack is a major problem when it comes to defining what the party is for and how we are to judge it.
There is a flaw in the motto "Elect More, and Better, Democrats." This motto of the liberal netroots--as a handy shorthand for the current generation of liberal activists--was laid out originally by Markos Moulitsas and adopted to various degrees by the other major netroots networks and organizations.It's worth a full read, which you should go give it.
The flaw is the word "better". With no real left ideology (and therefore, no attendant analysis of the current political and economic situation) there is no real way to gauge what makes a "better" Democrat. With no definition of "better" in this context, we are left with "Elect more Democrats;" not only this, but without an ideology--an analysis--we can't gauge legislative progress--meaning we will never know when we have "enough" Democrats. Electing more Democrats is not a worthwhile goal until we know what makes a politician a "good" or "better" Democrat.
That is to say, without a party-independent movement capable of providing analysis of current political and social crises, we'll end up with a constant tension between those who think espousal of particular issues, versus partisan loyalty, define "progress", "the left" or "progressivism".