How does the ideal American portrayed in Mr. Smith Goes to Washington represent American exceptionalism?

There are many elements to Capra's film that helps to
bring out the qualities which help to feed the exceptionalism so often associated with
America.  Jefferson Smith is the prototype of how Americans view themselves in the best
of lights.  He is an outsider, someone who selflessly devotes his life to civil service,
as evidenced with his participation in the Boy Scouts.  The fact that governor's
children support Smith helps to bring to light that part of the American notion of
exceptionalism is the myth that leadership comes from grass roots levels and rises
opposite to the establishment.  At the same time, Smith is besieged with challenges and
opposition from said establishment, including intimidation and accusations of
corruption.  True to the mythology of American exceptionalism, Smith continues and
perseveres on, fighting through a filibuster and fainting.  In the end, his good will is
recognized through a confluence of circumstances that prove justice and righteousness
wins and the forces of malevolence are recongized and punished.  The ideals that are
embodied through Capra's direction and Stewart's depiction help to bring out the very
best of modern American mythology, contributing to its belief in
exceptionalism.