No stone should be left unturned IMHO. There is no other way to build the kind of infrastructure necessary to produce the progressive victories we say we want at the local, state, and federal levels. Plus it's the only way AFAIK for "red" states to go "blue" (or at least purple). The only real drawback is that we will wind up with a few "blue dogs"- but, frankly, I think it's worth it when we can set the agenda.