I'm rewatching season two of The Wire for the fourth time, and for the first time it occurred to me that one could actually look up how the Port of Baltimore was doing in 2003 when the season aired:
(Maryland Port Authority)
Contrary to the impression given in the show, it doesn't appear to have been experiencing any kind of noteworthy decline. Now 2009 looks to have been utterly disastrous (thanks, global financial crisis) and there was a downtick in 2013. But 2003 looks to have been a fine year in the middle of a stretch of fine years. Meanwhile, just this week, a new $22 million roll-on, roll-off berth for cars and other vehicles opened that is positioning the port for further growth.
At any rate, the show is concerned with the fate of a specific set of workers and the overall shipping stats don't speak to that. But the checkers themselves certainly seem to think that their employment woes stem fundamentally from a decline in the larger vitality of the port, a decline that simply doesn't seem to be happening.