I recently argued in this space that New York State has no real political parties (with the possible exception of the Conservative). I saw nothing last night to make me re-evaluate that conclusion, but that is a talk for another time.
Unlike in New York State, there is something called the Democratic Party functioning nationally in more than just name. It is a broad based coalition, which, by its nature, is often divided. In addition, its hands are often bound by the nature of the peculiar institutions through which it operates, none perhaps more peculiar than the US Senate.
Most notably, is that, given the size of our nation, it is forced to operate locally through units of varying degrees of efficiency or even existence.