This panel from Captain America Reborn #5 would've been a nice end to my post yesterday, because it would've illustrated a point that I failed to make yesterday and that is that Captian America has always been a more-or-less liberal comic for decades.
Here we see the Red Skull in possession of Steve Rogers' body invoking the slogan of Ronald Reagan's first run for President (if the image is a little blurry I apologize for the quality of my scanner, I assure you the Skull-possessed Cap is saying, "TIME FOR A NEW MORNING IN AMERICA"). While like the Tea Party that got Ed Brubaker in so much trouble with FOX this is only a slight jab at the political right, it's part of a long tradition.
For example, back in the '70s Cap took on an ersatz version of himself that had been active in the 1950s (who is actually the villain in the Tea Bag issue, but that's another story) who had been a virulent McCarthyite. While the confrontation with '50s anti-Communism (which btw, was horrible and destroyed people's lives) was two decades late, it illustrates the point that Cap stands for a version of America that is inclusive and that protects civil liberties. It's from the vanilla multiculturalism of this ethos that brings us the Falcon as Cap's buddy. It's also what made Cap the perfect opposite for Iron Man in Civil War.