Really bad idea. Boston tried private fire companies over a century ago. You can still see some plaques on old home telling which fire company to contact in case of fire. The problem was that, but the time someone fired out who to contact, the building was in ashes. Why would private police be any different. Indeed, it would likely be worse.
This idea that Americans have come to take for granted -- that we need police officers to serve and protect us -- has no place in a free nation. This country was built by people who were perfectly capable of PROTECTING THEMSELVES.
The purpose of law enforcement isnt to protect the citizens at large. Its to ensure that accused criminals are apprehended and protected so they can be subject to legitimate trials instead of hunted down and given justice by armed vigilantes.
We -- including conservatives -- have forgotten this fundamental aspect of the U.S. legal system over the years. As a result, we no longer think of the police as law enforcement officers and instead see them as nothing more than armed security guards doing a job that we are too lazy and irresponsible to do ourselves.