Following WW1, which was considered by most Americans as a futile war of little importance to the US, the US entered a consensus (majority agreement) that they should adopt a policy of "isolation" towards Europe, which was increasingly unstable. The US public did not want to be drawn into another European war. Although, the US mantained strong economic links, such as the various economic bailouts and loans they gave to Germany's Weimer Republic and exported greatly to Europe.
Basically your answer is a Policy of Isolation.
Hope I helped :)
The undreground railroads
Because they <span>They resent to Aztec who had conquered them and demanded tribute to support the lavish of Aztec cities.
The leader of the Aztec of that time oppressed the member of their group with tyrannical rules. The resentment build up over the years and Cortez saw this as an opportunity to gained new reinforcement armies.</span>
They kind of do. That is because even though a party is strong nationwide or within a state, there are high chances that their votes will almost be irrelevant because the votes will go to one of the major 2 parties. This system can discourage them from participating.