In Pride and Prejudice, how has Elizabeth's prejudice led to her miscalculations of characters?

The character of Elizabeth Bennet has a penchant for
speaking out her own views of everything, and for forming strong opinions. These
opinions, however, she would later on treat as facts. Not only does she believe in these
facts, but she also defends them against the opinions of
others.

Although most of her views and opinions are valid,
there are some that she formulates without much substantiation. The most obvious one is
her overall opinion of Mr. Wickham.

Wickham's charms seem
to dominate Elizabeth, who hangs on to his every word and believes everything he says.
She even believes his sad story of how that "typical" bad, aristocrat Mr. Darcy took
everything away from him, leaving him no more options than to "lower" himself to join
the military.

Elizabeth's tendency to treat as a fact every
one of her opinions leads her to conclude that all aristocrats are bad and they all hurt
people because they are all money-hungry and snobby. Hence, in her mind, Mr. Wickham is
indeed Darcy's victim and Darcy is "the" prototypical mean aristocrat who hurts other
people.

This is an opinion that she continuously drags
throughout the story until the moment when she finally realizes (through Darcy's letter)
that Wickham is actually a liar, and a man with no backbone, nor dignity. This is even
more stinging when Wickham elopes with Elizabeth's younger sister, throwing away their
friendship and bringing shame to the family name.

Hence, it
is safe to assume that Elizabeth's problem is not that she is opinionated, nor that she
is a firm believer in her own thinking processes. The problem with her is that
she allows emotion to come in between reasoning sometimes. This is why, in the end, she
learns her lesson in the hardest of ways: Through the shameful situation of her own
sister.