Pour some cement on the mushy middle
Atrios dispels some myths about "independent" and "swing voters":
I think the big issue here is the perpetual confusion of "independent" and "swing voters" with some concept of "centrist" or "moderate" which is generally put out by the press, when in reality these people are often low information voters who are likely to vote for someone "who knows what s/he stands for" instead of someone who has mushy middle distinctions-without-differences policy positions. There are tribal Democrats, tribal Republicans, and some genuine "can be convinced on the issues" voters. But most of the people up for grabs "in the middle" aren't really in the middle in any sense that we understand it. Instead, they vote their gut and are proud of it.
Besides, if you run a mushy middle candidacy, they're still going to run commercials calling you a crazy liberal who's going to make your son marry a dude and raise taxes to 100%. I see it happen over and over.