If I had thought about it a bit longer, it might have occurred to me that the movie was made two years before Prohibition ended. In fact, the story is centered on exactly the kind of criminal who arose and flourished during (and largely because of) the enforcement of the Volstead Act, so in a sense it's as much a movie about the Prohibition phenomenon as about Cagney's character, Tom Powers. Prohibition is undeniably one of my pet favorite historical interests, so that made the movie especially intriguing to me, as a contemporaneous document of the era unfiltered by latterday perspective. (I was especially amused by the matter-of-fact scenes of rampant stockpiling, bordering on rioting and looting, on the eve of Prohibition's enactment, which very much conveyed what it must have felt like to live through that event.)
The greatest surprise for me in the movie was that its overall tone was, for lack of a better word, fairly objective. There are moments of that are funny, and moments that are thrilling, and moments where a moral and social message is beaten like a drum, but all in all Tom Powers is portrayed as a realistic person, not an object of ridicule, nor a folk hero, nor an unfathomable monster. The story begins during his childhood, with a mother who dotes on him and a father who beats him, living a hardscrabble life, all of which provides context for how he might become both cynically embittered and eager to rise as quickly as possible to greater wealth, power and respect. And he eventually gets there, at tremendous cost.
The above has to be one of the most iconic images from the movie (possibly from all movies) but seeing it framed by the larger narrative is fascinating. It's just one more example of Tom Powers lashing out, because he's got a mean streak. He doesn't really gain anything from it, nor does he really pay for it - unless you consider his brutal (offscreen) murder at the movie's conclusion to be comeuppance for every act which precedes it.
The acting (outside of Cagney) and the direction are nothing special, to my eye, so it's not as though The Public Enemy is a keeper in terms of pure artistry. But as an unsparing, unsentimental document of the dawn of American gangsterism, however fictionalized, it's well worth remembering.