I would argue that we need to appeal to as large an audience as possible and shouldn't necessarily look at including or excluding anyone based on which "groups" they belong to. Groups have a wide variety of members who have a wide range of ideologies and beliefs. I think we lose if we narrow our focus too far in the pursuit of, for lack of a better phrase, ideological purity.
Of course, that doesn't mean that we should appeal to, say, white supremacists. But, from a higher level, I don't think we should summarily dismiss groups based on stereotypes or simplistic views of what they represent. This kind of dismissal is pretty common, particularly in a partisan environment like DU.
For example, there's been much consternation about Joe Biden and others appealing to moderates and even some disaffected conservatives by indicating that they would try to work across the aisle to get things done. The knee-jerk response is often that bipartisanship doesn't work in our current environment, so why bother, yet most of the bills sitting on Mitch McConnell's desk were at least somewhat bipartisan in some form - either they were co-sponsored by at least one Republican or had some Republican support.
That doesn't mean that we're going to get them to work together on major legislative items, of course, but we need to understand that many, many people are largely apolitical and/or highly dislike the hyper-partisan nature of American politics. We're not going to appeal to those people by being even more hyper-partisan.
Similarly, writing off moderate Democrats or Democrats who are in states that we won't win in November is misguided. Down-ticket races can be extremely important, especially in places like Texas where, while we're unlikely to win the state at the presidential level, continued momentum in retaking the state legislature should be a primary goal, and there are many House and Senate races that are important in our quest to retain and regain those houses. Battles like that will take place in many states where our nominee is unlikely to win. There's more to this election than the top spot.