Big cities vote blue because there are more people in big cities compared to small towns. The majority of people in general vote blue, as seen by the popular vote in the last 8 presidential elections.
That doesn’t mean that is the reason why there is more crime in big cities. Correlation doesn’t equal causation, it doesn’t matter how many times Fox News repeats it.
There is more crime, homelessness, and poverty in big cities because there are more resources in big cities. More shit to steal, more shit being donated, and more competition for said resources, which leaves some without much. This isn’t a new concept. If you look at a lush abundant waterhole in Africa, you’re going to find more water buffalos, more lions trying to eat those water buffalos, and more hyenas trying to get scraps from those kills. What you won’t find is some dumbass elephant trying to convince everyone that it’s the donkeys fault it’s all happening at the waterhole.