People are irrational, it's not just an American trait. That item 5 does imply that a fairly large number of voters believe that their vote doesn't count or that it is best used as a "protest" of its own. If you stay home because Hillary is a bad candidate, you might get President Trump. If you vote Trump even though you think he's a potential disaster, you might get President Trump. If you vote third party as a "wake up call" for the DNC, you might get President Trump.
"Well, evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts don't go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's in this century, but apples didn't suspend themselves in midair, pending the outcome. And humans evolved from ape- like ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered."
-Stephen Jay Gould
-Stephen Jay Gould