Usually they need votes in order to get elected and change the law about votes..
Americans are not a homogeneous group. You've got rich peple who play golf and sip the latest in brandies and you've got an unemployed hispanic mother of three or even seven!
But I agree - it depends on the person. There are different factors that determine if a person is easy to manipulate with. Poverty, education, relations, mentality, severe emotional traumas....these factors interact. Some have greter influence than the others. In my opinion poverty is one of the most influential factors.