I'm with you. I don't understand the MOE.
The margin of error for a poll is a statistical term that reflects ONE THING ONLY. Namely, it reflects the number of people who participated in the poll.
In essence, the margin of error says:
The margin of error is an estimation of the extent to which a poll's reported percentages would vary if the same poll were taken multiple times. The larger the margin of error, the less confidence one has that the poll's reported percentages are close to the "true" percentages, i.e. the percentages in the whole population.
Again: despite the misinterpretation that it reflects the actual accuracy of the poll, it is NOT!!!! that. As given in the media, it is ONLY a function of the number of people sampled for the poll. That's OK, if you understand the assumptions and limitations behind that.
The basic idea is that pollsters are sampling from a known population. There are many, many assumptions that go into poll results, and if you understand them, you'll know what to distrust about them.
The biggest, and least trustworthy, assumptions are that the people sampled for a poll are a random and representative sample from the overall voting population.
Another huge assumption is that the pollsters know the characteristics of the population from which they're selecting samples. For example:
a. They know how to factor in things like party loyalty
b. They know the proportions of R's to D's to Independents
c. They can actually reach people who represent those proportions
d. And the BIGGIE: that those responding to a poll are giving honest answers.
The extreme variability among the various poll results, and the secretive polling processes used by each organization, show that nobody is meeting those assumptions.