Captain America: Heavy's the Head That Wears the "A"

No one can begrudge a good Hitler-slugging, but such imagery commonplace in the 40's is seen as a vice today

Marvel's "top tier" of superheroes has been a bit amorphousness over the years. For years, Captain America was part of the resident Marvel Superheroes "trinity" that included Spider-Man and the Hulk. However, Cap would, over the years, find himself displaced by Wolverine, sometimes the Silver Surfer...even Iron Man as of late. He's certainly one of the company's, even the superhero genre's, most iconic figures, but he can suffer large wanes of popularity. Being a straitlaced hero can certainly see your popularity eclipsed with the younger set. Especially when you're treated more like a sentiment than a character in your own right.

I sometimes wonder what it would look like if the legal (and thus, cosmic) parameters that keep the Marvel and DC Universes separate were broken. That is, Superman and Spider-Man were part of the same narrative tapestry, and could interact with each other as frequently as they interact with the Green Lantern or the Hulk, respectively. I imagine a lot of redundancies would be eliminated, or re-imagined. (It's interesting to note in the most analogous examples, namely the dual trinities of Flash/Aquaman/Green Arrow vs. Quicksilver/Submariner/Hawkeye, the latter half have served as career villains at some point) The question that most often pops up is where Captain America would find himself in this new world order. And, as pop-culture in general is amalgamation that cares not for "universes", where he finds himself as a figure.

The idea of Marvel, in contrast to DC, is that its roster of super-powered champions are motley outsiders. Flawed, ornery, or a least antisocial, they're not pinnacles of humanity, so much as alternatives to it. Captain America is the glaring exception. A remnant of the golden age, bright, shiny, and as far from "weird" as you can get for comic book character. Rather than tear that concept down, Marvel has instead made him the stabilizing force of the chaotic Marvel Universe. His leadership is not that of a Type-A dictator, but of a reluctant but obliging Cincinnatus, who carries out actions while Reed Richards, Tony Stark and Professor Xavier pontificate. The "dad" of whatever collection of heroes we're working with. In-universe, he's an inspirational figure. He's there to organize a strategy, to give a pep-talk to heroes about their doubts, even as he wrestles with his own. Basically, he serves the purpose that Justice League's "trinity" serves.

Some of the Star-Spangled Avenger's venture outside comics have been..ignominious to say the least.

Which is probably why writers are often at a loss what to do with him outside the big crossover events. In a lot of ways, he's like King Arthur, who in modern fiction rarely serves as the protagonist In most takes on Arthurian lore, Arthur Pendragon is a supporting player, sometimes a background figure. Focus is not so much placed on Arthur, who remains a static figure. That's not to say a perfect figure, but somebody who's inherent goodness inspires the action, as opposed to triggers it. Occasionally we'll get an Arthur who's lost his way and our main character must re-inspire him. But ultimately Arthur is about ideals, both the strength and fragility of those ideals. Captain America often serves the same purpose in comics. There's always a sense that as long as Captain America is going to be around, even as the character is plagued by doubt in his own stories. Captain America is usually popular (Or merchandisable) enough to maintain a title continuously, but usually not popular enough to franchise, Thus, the majority of his appearances are usually about his places in the Big Picture.
In fact, even the most well-regarded runs in Captain America's own title, like Mark Gruenwald and Ed Brubaker's, usually have half the arc consisting of somebody else having to fill in Captain America's shoes. It's not so much they don't regard Captain America interesting--the stories aren't about Captain America is a closest sadist or something dark to tear him down. It's just the belief that Cap has come to who he is honestly, and while he weathers self-doubts, they're less about growth. Cap doesn't need to grow anymore as a character, he doesn't need to learn a great deal. Just the occasional sobering or humbling moment, before he's back to being an inspiration to everyone again.

Even his ostensibly sol title had someone sharing the bill.

That character schematic, however, is dramatically difficult. Especially when bringing it to another medium. The Punisher, Captain America's polar opposite in so many respects, has had three movies made about him, with very little success. Some comic fans say that it is the result of the Punisher not being particularly unique outside a superhero universe to contrast him. This may have been the same problem with Captain America, He's the superhero most superheroes want to be; But that's supremely difficult to convey when the superpowered populace is kept to a minimum in said adaptations. There are no superheroes to contrast against. Even his innate nobility is harder to convey, because to a certain extent, Captain America;s granduer was built up over  long time. Introducing him for the first time may not have the meaning he does for comic fans. Many grow to appreciate him over time, but such investment is hard, maybe even pointless, for other mediums not as long-reaching as serial comics.

It's perhaps no surprise Captain America has not had a long-running series, even a cartoon show, since the 1960's Marvel Superheroes cartoon. (Which barely even count...the show was photographed comics slightly edited to mimic animation) But he's guest starred on roughly half the cartoons made about these characters. (Even the X-Men ones, which were always notoriously insular.) Part of that is simply the WWII background, much like an isolated valley of dinosaurs or "underwater episode" will provide instant guest stars. Still, the aficinados who run these programs likely have that moment at the brainstorming table of "Hey, we have to have Captain America."

Historically, Cap has been "Mr. Avenger", although Iron man's cinematic popularity has complicated this.

Of course, his tendency to be a guest star more than a main character might owe itself to the complexity of politics. In the hidden corner of comics, one can go on more adult political screeds, to say nothing of more liberal ones. Recently Ed Brubaker came under fire for a quick shot at the so-called Tea Party, claiming Marvel was using the American flag to further their agenda. Of course, Captain America has always leaned rather left--Steve Englehart's treatment was a campaign against Nixon America and the McCarthy era. Even his conception was that of an FDR-era hero. One may argue his coming out party of socking Hitler straight in the jaw owes more to his creators being two New York Jews, than any sense of American Exceptionalism per se. Much of his richer stories explores this divide, and it may be as problematic, or at least as difficult, to get into the Red Scare on a children's show as it would to explore King Arthur's incestuous siring out of wedlock. It's certainly made movie producers nervous, in a climate where "agree to disagree" is a lost art.

Captain America's first official foray to the screen has him almost completely in the context of how he fits into the Avengers, even down to "The First Avenger" being the movie's subtitle. On some level, a bit of an insult to die-hard fans, and to those who feel it's political correctness gone awry. But in other ways, it could be seen as playing to a strength. The Avengers are Marvel's premiere team, and Captain America is the premiere team player.