Ed Kilgore on the big survey of independents:
You should read the whole, elaborate thing, but the great utility of this survey is its typology of independents, who are neatly divided into five "D's": Disengaged (24%), Disguised Partisans (24%), Deliberators (18%), Disillusioned (18%) and Dislocated (16%). [...]
Overall, the survey casts a lot of light on some of the more outlandish claims about indies. They are not frauds or irrelevant, to be sure, but they are also not a centrist monolith that Democrats can win simply by moving to the right on this or that issue.
But, look, a huge proportion of them actually are frauds ("disguised partisans") or irrelevant ("disengaged") especially since I'm willing to wager that a non-zero fraction of the "disillusioned" are frauds, irrelevant, or both. It's just that when elections are really, really, really close you need all the votes you can get, so that even if "deliberators" are only a tiny slice of the electorate their views are still very important.