Re the politics, a good article on the subject -- and one of the few reviews of the time that bothered to take the show's success seriously; most of the reviews were as nasty as those for Gilligan's Island two decades earlier -- is this article which appeared in England's New Statesman magazine in 1983. (The A-Team was and remains enormously popular in the UK.) The politics of The A-Team boiled down to three basic points: a) Vietnam Vets were screwed over by the government in Vietnam and continue to be screwed over back home, b) The police and the government can never solve any problem; for real protection what you need is a group of armed "soldiers of fortune," and c) America is great even though the government isn't. (Asked why he and his buddies haven't fled to Switzerland, Hannibal replies: "Because we're not Swiss. We're Americans.") As the author notes, in that tut-tutting New Statesman way:
This is classic right-wing American populism -- patriotic, macho, anti-authority -- and is unlikely to be understood in Britain, where to be right-wing implies an obsequiousness towards officers and the status quo.
This kind of "right-wing populism," and in particular the celebration of vigilante justice, had been a staple of movies in the '70s but hadn't been seen much on TV; The A-Team brought it onto TV, and many action shows that followed were either about vigilantes or cops who acted like vigilantes (e.g. Cannell and Lupo's Dirty Harry knockoff, Hunter).
But what made The A-Team popular wasn't that it was populist, but that it was fun. As the New Statesman reviewer notes, a lot of it plays as parody, and the show was in large part a comedy; it was, after all, the show where nobody ever got killed in spite of all the violence, and where the plot was secondary to the jokes, as Cannell himself pointed out:
The story each week was secondary to the dynamics of the characters. We told one story over and over again - our prototype lantern-jawed heavy would try to take over somebody else's property, and the A-Team would roll into town and decimate them. It was always the same show, but we'd have different character things playing between our guys every week. Because really it's a comedy.
Two other points about this shamefully enjoyable show:
1. The fun of the first season (which I'm told looks good on DVD but doesn't have any extras) is that you can see the writers actively looking for a formula. Each of the first few episodes is in a different genre of action story. The pilot, which has a bigger budget, better dialogue and a different Face Man than the rest of the series (Tim Dunigan, who is less irritating than Dirk Benedict but who suffers from being taller than Mr. T, thus reducing his impact), is basically The Magnificent Seven. The first regular episode, written by Cannell, is a surprisingly dark and somewhat tasteless takeoff on the Jonestown cult (here called "Jamestown"). Then comes another Cannell episode, "Pros and Cons," a genuinely hilarious takeoff on every evil-prison-warden movie you've ever seen -- this is the one with the famous cry of "TRASH BAGS! I WANT TRASH BAGS!" Frank Lupo turns in an episode where the A-Team fights an evil alternate A-Team of rogue cops, and another episode, set in Las Vegas, is basically a Mission Impossible ripoff from beginning to end. Oh, and there's a hugely entertaining episode where they defeat an evil biker gang in a small town, an episode that uses the same basic plot as a Knight Rider episode from the year before. (The Knight Rider episode was called "Good Day at White Rock"; the A-Team episode is called "Black Day at Bad Rock.")
Finally, in mid-season, they do a couple of episodes where they hit on the winning formula -- the A-Team helps save a farm/ranch/business from being taken over by some evil dude who wears a cowboy hat -- and they would stick to this formula in nearly all episodes from then on (until the final season, when it was retooled). Part of the reason the first season is the best is that you get to see the characters in different kinds of stories, even if they're mostly recycled from other sources. A lot of '80s action shows were like this: they'd experiment with different types of episodes, hit on a formula, exploit that formula shamelessly throughout the run, and then desperately try to get away from the formula by the end of the run, by which time it was always too late.
2. I know this is bizarre, but I always feel sorry for Amy (Melinda Culea), the "token female" of the show in the first season. The pilot presented her as a potentially interesting character, written more or less like a Howard Hawks heroine, and then she had literally nothing to do from then on. She was fired in the middle of the second season in the most humiliating way possible (she got a script and found it had no lines in it for her character) for the most humiliating reason possible (George Peppard took a dislike to her and turned the rest of the cast against her). Yeah, I know a woman, especially a woman who had no connection with Vietnam, had no business being on the show in the first place, and that she was only there because of the belief that every show needed a female character. But the character really worked in the pilot, and with a bit better writing... well, spilt milk.
Oh, one more thing: Cannell (who produced this and many other shows independently) apparently started to run out of money toward the end of the first season; you'll notice that the last two or three episodes of the season cut corners by using stock footage, redubbed footage from earlier episodes, and even a shot from the movie Airplane! Actually, The A-Team had as much in common with the Zucker Brothers as it did with other works of "right-wing populism"; it was, above all, a funny show, and Cannell's imitators (like the totally-without-humor Glen Larson) never really got that.