What is the function of populism?

The main function of populism is to allow the ideas of a
certain set of the "common people" to be heard and to allow that group of people to feel
as if they have a voice.  This can be seen in many ways with the Tea Party movement
today.

Populism is an ideology that stresses the virtue of
the traditionally-minded "common people."  It asserts that their instincts and values
are superior to those of both the elites and the poor (particularly, at least in the US,
non-white and immigrant poor).

Today in the US, we see this
dynamic at work in the rise of the Tea Party.  Members of this populist movement assert
that their values (self-reliance, belief in small government, traditional social values)
are what made the country great.  They argue that elites (Obama, Bernanke, the bankers,
liberals in general) and the poor are combining to destroy that
greatness.

Populism functions, then, to give a voice to the
"silent majority" of common people who see themselves as the backbone of the
country.