Of course it is much more than a cop show; it digs much deeper into the societal aspect of both the cops and the crooks. After trashing that very notion above in regards to The Sopranos, I say that advisedly. The last thing The Wire is is a clichéd recitation of some New York Times op-ed or political activist harangue. Life is never cut and dried or anything less than complicated beyond understanding. The Wire does not gloss, and it does not condescend. Problems are rarely solved. Some people progress, some regress. In the end, the only thing that counts is enduring.
Dramatically, The Wire violates many standard principles of television. According to creator David Simon, each season is conceived as a single novel instead of a group of short stories. There need be no individual hour long story arcs. A given episode may not contain a resolution even for the smallest subplot. The result is that The Wire can seem slow, especially during the beginning episodes of a season. Tension builds throughout the season and the payoff doesn’t really come until the last three or so episodes. More importantly, it also means that each season is conceived as a whole, with a coherent and known ending. There are common characters from year to year, but the show is not about them other than peripherally. The second season was about economic upheaval that has hit certain industries. The third season was about the war on drugs. The upcoming season will be about education. Simon clearly has opinions about these issues but he never proselytizes. All sides of the story are fully human; peopled by folks reacting to the world from different directions and in ways that put them in conflict.
The Wire has never been a ratings success. In fact, their renewal for a fourth season was in jeopardy for quite some time. It would be a surprise if it was popular. The casual viewer would see it as plodding. And you can’t pop in half through the season or catch a random episode now and then and have it make any sense. But if the notion of conceiving a TV show as a limited piece of work with a defined end point will become an accepted practice The Wire will have been the pioneer.