Why do police in sanctuary cites such as SF allow illegals the privilege of driving without licences?

It's mostly political-based. There are so many liberals in California (and this is a good place for them), so the state government is biased towards supporting illegals and most large cities in CA have a major wetb*ck population. So what I'm saying is that not only does the state and local governments cave in to the liberals and let things slide (let illegals drive and vote and go to school), but so does the federal government given that it depends heavily on CA during election time.