On Wednesday, Newsom, a Democrat, endorsed legislation that would ban people from carrying guns into churches, public libraries, zoos, amusement parks, playgrounds, banks and other privately-owned businesses that are open to the public. The rule wouldn't apply if the business owner puts up a sign that says concealed guns are allowed.
This proposal would ban guns in all private businesses. IOW, ban guns in every place where a shooter would be likely to shoot. It would almost entirely leave Californians undefended.