Non-American comic nerd right here. I'll answer that question right now;
To my mind, Captain America does not symbolize 'America' the bit of dirt, or even 'America' the political nation. He represents 'America' the IDEA; Freedom, justice, Libert and all that stuff. You know, the stuff that went out of fashion durin the bush years. Conversely/similarly, the Red Skull doesn't represent Germany, he represents Fascism.