Also re solutions/redemptions
I assume Carcetti will have an icarus-like fall but at this point (& I'm at the end of S4, the "New Day in Baltimore" area) there's a meaningful difference between administrations. The main problem with the previous policework was a mayor who didn't give a shit about efficacy, just the appearance of efficacy & pleasing stakeholders, so he ends up appointing bullshit commissioners and bullshit deputies and then pressures them to juke the stats.
This isn't "corruption" in the traditional sense of the word, but it's damn close, and it's at the heart of the problems of The Wire.
The other problem is an uneven quality police force—the way Sgt Haulk fucks up the entire Marlo Stanfield case, and gets teenage witnesses killed, in S4, is the biggest most predictable shitshow. But again, why is the unit bullshit? Because Rawls assigned a bullshit manager knowingly and on purpose to wreck the major crimes unit. Why is Haulk a sergeant? Not cuz he passed the test but because Mayor Royce gave it to him as a bribe.
Which is in some sense almost too optimistic—all the problems stem from bad administration! Just make sure you have good leadership, no problem! My expectation for S5 tho is we see Carcetti inevitably repeat some errors of his predecessor, if only because, at the end of the day, he too is ruled by the tyranny of optics, the necessity of good appearances that comes with advancing politically. In that sense, the problem becomes more systemic