Agreed.
One thing that's very interesting about US politics is that, regardless of income, most people consider themselves middle class. People making 175k a year will often say they're "middle-class" in polls, as will people making 22k/yr. If you don't believe me, look at this -
http://www.theatlantic.com/politics/archive/2013/08/why-americans-all-believe-they-are-middle-class/278240
Politicians know this, so that's why they only talk about the middle class. There's sort of a stigma against poor people (by right-leaning people) and against rich peole (by left-leaning people) so politicians usually like to play it safe and just talk about the middle class since most people think that's what they are anyway. Plus, a lot of people on the right already feel like the current social safety nets (ie. food stamps, welfare) are already sufficient for the poor. Romney in his campaign said himself "I"m not concerned about the very poor".