Even the national race for president is decided at the local level on a state-by-state basis in America (as you obviously know), and therefore that whole argument regarding "Progressive" versus "Establishment" candidates holds very little water, and Independents (also known as "swing voters") primarily decide elections.

Having said that: "It's the economy, stupid" also applies, and Independents, non-affiliated and swing voters will generally turn out in greater numbers to "vote the bastards out" and not generally concern themselves with the degree of "Leftiness" or "Rightieness" (invented words) of the opponents of the perceived "bastards."

To MtnCaddy specifically: There is no such thing as the "Republican wing of the Democratic Party," and you should be glad of that fact. :)