BTW...I didn't see anyting in the Constitution about speed limits, drinking on Sunday or attending Synagogue.
Read Amendment X, "The powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people." Speed limits are state laws. Congress doesn't set speed limits (legally, at least), the individual states do. The individual states pass laws regulating the sale or consumption of alcoholic beverages, or else the states pass enabling legislation to transfer that power down to county or municipal government levels.
These misunderstandings are prime examples of why liberal talk radio is so difficult to sell. It's why so few people with a liberal political outlook want to spend time listening to liberal news/talk radio. Listening to any sort of news/talk radio, regardless of the political bias of the host, requires a certain level of interest in politics and government. To find such talk entertaining, one needs a certain level of understanding of the issues, which can be complex. It is very difficult to find someone with a liberal political outlook who also understands how the US government works, because once one learns how government works, one sees that liberalism won't work.
Compare news/talk to sports/talk. How many people would choose to listen to sports talk radio programming who know little or nothing about sports? How many people would choose to listen to sports talk radio programing who don't care about sports, or who have no interest in sports? Politics aren't that much different from sports.
The relative handful of people who are knowledgeable about politics yet who remain liberal in their outlook aren't numerous enough to form a viable mass audience for liberal news/talk radio programming. True, there might be a few markets in the country where such individuals tend to gather in larger numbers. In those isolated markets, liberal news/talk radio has a better chance of success. But the existence of such isolated, non-typical markets is not proof of a larger, nationwide opportunity for such programming.