You see it publicly and more vociferously after an election.
They are very successfully manipulated to vote for people who will deny benefit to people like themselves in the (sincere, induced) belief that it would mean taking from themselves to give to people even lower.
It is the bedrock principle of "conservative" politics, that successfully keeps the upper class from ever needing to pay their fare share. The underclass have been taught to carry them on their shoulders, and like it.
[1] Half of eligible voters don’t even vote in federal elections. And propensity to vote correlates with socioeconomic class. You say “underclass”. Well, is someone from the underclass more likely to vote R? Or not vote at all?
95+% of Americans are underclass. (Between 1945 and ~1975 there was a pretty strong middle class. By 1990 it was gone.) Of those of them who vote, about half vote for each party. The rest, who knows?