This photo was on HuffPo representing a tea party rally. I must respectfully ask that tea party people please stick to the tri-corner hat costumes and leave the superheros out of it. Captain America would probably come down on the Republican side, but he is no tea party guy. He is straight-laced but compassionate.
The photo caught my eye, but the article was worth reading.
http://www.huffingtonpost.com/2010/11/23/tea-party-poll-elections-2012_n_787887.html
Hope the exit polls and AP polls they are citing are good surveys… if so it is promising to think that only 30 percent of adults are supporters of the tea party crowd – but that 60 percent of Republicans align with the tea party. If the Republican party shifts hard right to please that 60%, then the 70% of adults not supportive of the tea party can regain ground and perhaps quiet down some of the yelling. Although, that 30% sure makes for good TV…
Cog in the Wheel 
The Marvel character of Captain America has stated numerous times in the last 50 years that he is not about either party. He is all about the idea of America itself. A lot of flak was given the comic recently when Cap broke up a violent militia. Seems the letterer filled in their protest signs with recognizable Tea Party rhetoric. Cap is neither left nor right but it is a pretty safe bet that Marvel has a left-leaning bent and would not want Cap used in such a way.