The problem with constitutional, parliamentary democracy is that the bulk of the government is an bureaucratic, administrative structure which is not elected, and doesn't change. Thus, the entire government, as such, actually isn't democractic at all. Most of it just cares about its job security more than anything else, and also about ensuring the most funding for its own division. If you understand this one thing, a lot of politics falls into place.
Partisan bureaucracies are even worse. Imagine the new governor firing most government employees and replacing them with party loyalists. It was called the “spoils system.”
