One or two cities is not "Democratic policy." And the issue is balancing punishment for minor offenses against enabling a few organized crime rings to operate - "lock 'em up" happens to be highly expensive (more taxes) and there's a shortage of prison personnel in a tight economy. Yes, Progressives display an appalling lack of common sense (ideology over evidence based policy) but so does the "Right," at least Progressives are decent if misguided people, "there are good people on both sides" chanting "Jews will not replace us?".
There are a few stupid but symbolic gestures by leftward leaning states and cities, such as sex change therapy for minors which has become ideological when it's a medical issue (some European countries have stopped it b/c minors tend to be confused about their sexuality and medical procedures have serious consequences, one of the issues where ideologues on both sides should STFP and medical evidence collected). The Left is in love with invented "rights," because that allows them to avoid compromise - the mirror image of the "Right" and their religious based ethical mandates - "rights" don't exist because of Enlightenment philosophers or the Bible or Koran, they're created by society, by law (Constitution is higher law) and thus requires a general consensus.
Immigration is a plague on both your houses, Republicans haven't wanted to crack down on large breasted East European immigrants for example, who overstay their visas (as many come through airports as over the border) - real immigration reform requires compromise, including say funding for doubling the number of asylum judges so applicants can be processed faster and deported, resolving DACA once and for all (sending back children who only speak English would be cruel and stupid), cracking down on Visa violaters, etc. Work programs for agriculture and so on.
We do need to secure the borders, both those from the South but also those flying in. This isn't the 19th century, there are no more Indians to kill and take their land to be sold to immigrant farmers - if poverty and crime are grounds for asylum, get ready for a billion immigrants - and immigrants who come from poor rural areas are harder to assimilate and less valuable economically - compare the Vietnamese middle class v the boat people, same with Cuba, or Iranian refugees from the Ayatollah to Syrian peasants. And as the Israelis have found out, a large group of religious fundamentalists and people who come from countries with authoritarian traditions can completely change your politics and culture. Both Muslim and Christian fundamentalists are opposed to the 'live and let live" ethos of the West. I want neither of them.