...I'm not a registered member of the Democratic party. I can't speak for anyone else.
I'm not a joiner. And there are way too many things that I disagree with the party about. Frankly, I don't like the two party system. I think we need viable third parties. For the most part, the Democrats have been captured by Corporatia just like the Republicans. And I suppose that's partly my own damn fault.
Here in New York State, you can be on the ballot on more than one party ticket. So, for example, in 2008, I did not vote for Obama on the Democratic ticket. I voted for him on the Working Families Party ticket. That allows me to support what I feel is a real, progressive third party, but the Democrat still gets elected. I like my Congresswoman (Nydia Velazquez, NY 12) and although they are beholden to Corporatia, my senators, Schumer and Gillibrand are all right.
So I think the numbers are skewed. I vote for the Democrat every time, but I'm not a member of the party, and given the chance, I will vote for the Democrat on the WFP ticket.
However, I don't think there are all that many others who do it the same way I do it. I think for the most part, the vast majority of Americans simply don't care about or pay attention to politics, and just vote the way Dad voted, the way Hubby votes, the way the TV tells them to vote, or they vote against the pussy or the black guy or the fat chick or whatever. Here at DU we live in a bubble and we actually pay attention to what is going on, and try to form our opinions based on something real and tangible. Most people don't do that.
Hope this helps...