The other aspect is that political activism in the US is safely channeled into the two major parties in a divide-and-conquer system. Everyone else is marginalized. Who wants to be discredited, marginalized, and considered a kook? For Democrats, Republicans are always the greater evil and must be opposed no matter what their own leaders are doing.
People are self-interested and dissent could be threatening to their livelihood. Foreign policy does not directly affect people in the US because we are protected by two oceans. Americans like to win, and when their side is winning, they don't care much for how.
So to summarize, politics in the US is channeled into the two major parties through disenfranchisement and ridicule of everyone else. Dissent is only possible within the two-party system by opposing the other party. Democrats have been browbeaten into supporting the US military for decades. 9/11 traumatized the population and opposing the Global War on Terrorism (GWOT) was defined as being a traitor.
Working on behalf of oppressed minority groups became the only safe way to work for change. Anything opposed to the US military, corporate, or political empire became defined as being a traitor. No one wants to be accused of being a traitor. So the Democrats fell into line in support of the empire. That's the best I can do. Please comment if my explanation falls short.
(Article changed on February 15, 2017 at 14:09)
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