>They don't take care of crime. They let infrastructure decay. The schools are crap (despite high per-pupil spending). They make crony deals with the unions on pensions and benefits that are not possible to fund.

To expand on this point, why would there be any institutional will to take more than a token effort to do any of those things? It's not like they risk getting voted out by someone who isn't on the same side and will leave the root system of the party's power to control government mostly intact (doing the opposite would anger enough people to not be in the self interest of anyone who gets elected).

Even if you keep voting in different politicians who actually want to do anything you're never actually getting a major refresh until you get someone from a different party who aggressively appoints a different set of cronies.