There's a combination of issues. In general, the US has a major crime/homlessness problem due to the lack of a social safety net, poor drug & mental health pol

There's a combination of issues. In general, the US has a major crime/homlessness problem due to the lack of a social safety net, poor drug & mental health policy, and homophobia. California has much nicer weather than much of the US so homeless people move their or are just able to survive there. In some cases, right wing states purposely relocate their homeless to California. America is currently experiencing a backlash against a broken justice system that tolerates police brutality, favors the rich, and is often racist. Unfortunately, this has probably resulted in an overcorrection in many places. The previous point is exasperated by the fact that the Republican party, which in recent decades has been more oriented around "law and order", has become a far right party. Therefore, even if someone agrees with their candidate on crime, they may disagree with them on economics, LGBTQ rights, etc. I don't know if this is true, but I've been told that unlike most other cities, much of SF's resources for helping homeless people is located in their downtown. That then results in the homeless problem being much more visible there.