CCW without permits is useless in cities since a state permit is needed to avoid violating the federal 1000’ gun free zone law around schools. I doubt that it is possible to drive through Madison or Milwaukee without passing 1000’ from a school. I don’t disagree with the constitution argument but the only practical way around the federal law is to have a permit from the state you live in, and states where you routinely carry.
There are a couple of realities that mitigate this. First, the federal law is almost never enforced, probably because the last time the law was tested at the Supreme Court level, it was ruled unconstitutional(1995). Thus, the federal prosecutors seem wary of bringing forward prosecutions that offer a good case to contest the law.
Second, local officials are almost never worried about violations of federal law. For that reason, in Wisconsin, it is the insanely stupid State law against guns within 1000 feet of a school that we need to repeal.