For the homeschoolers

High-level review for those who forgot (or who never read their Zinn in the first place):

1) You basically have four social/economic classes: a wealthy "ruling class," a truly impoverished underclass ("the true poor"), a "working class" that is only slightly better off than the poor, and then a "middle class" that has enough wealth to live comfortably but is far, far beneath the ruling class and cannot realistically aspire to join it.

2) The ruling class is tiny--a vanishingly small percentage of the population (e.g., "the 1%").  But it has all the power and enough wealth to remain perpetually wealthy through low-risk investment.  A few are so greedy as not to be satisfied with this, but most just want to maintain the status quo and will vigorously oppose anything that threatens their wealth and status.

3) The middle class tends to be politically conservative because they basically "made it" within the realm of economic feasibility.  They may aspire to someday join (or for their children to join) the ruling class, but mainly they perceive themselves as having a lot to lose.  The size of the middle class has fluctuated over time; it probably reached its apex during the post-war boom years and is currently down at or near usual historical levels. Common economist estimates of the U.S. middle class are basically useless because they are usually based on income levels rather than wealth, fail to distinguish between middle class and working class, and are often driven by arbitrary markers such as the U.S. federal poverty guidelines or round numbers like "$200,000 per year."  A more realistic view comes from things like the recent studies showing how few Americans can afford an unexpected $400 bill, or that 78% of U.S households live paycheck-to-paycheck.  So I will estimate the current (well, pre-COVID) middle class around 20-30%.

Source: U.S. Federal Reserve

4) The majority of the population belongs to either the "working class" or the true poor.  All of these people are some degree of poor and have very limited economic prospects, save for the occasional pop star or athlete or whatever.  So they basically have nothing to lose from disruptive political change and potentially much to gain.  They are so numerous that, were they to unite and vote together, they could dominate electoral politics and demand a much more just distribution of wealth and opportunity. 

5) The ruling (and middle) class understands their numerical disadvantage, and thus engage in constant and relentless efforts to divide the working class apart from the true poor and keep them divided.  Historically this has usually been done through demonizing particular racial, ethnic, or cultural groups, blaming them for the collective poverty of working class members, and treating members of the demonized group so poorly that the working class members (who are not subjected to such treatment) will perceive themselves as materially better off than the demonized group.  This process has historically played out in pitting Europeans against Native Americans, poor whites against black slaves--and later against free blacks, Asian immigrants, and now Latin American immigrants.