What was the importance of the class conflict in the Italian Renaissance?

In today's world, when we think of class conflict, we tend
to think of the poor in conflict with the rich.  In the Italian Renaissance, however,
the more important class conflict was between the merchant class (many of whom were
quite wealthy) and the nobility.  This conflict helped to shape the
Renaissance.

There are at least two ways in which this is
true.  During this time, the merchant class was getting richer and more important as
cities' economies came to be based on trade.  This led them to demand political power to
go with their economic power.  In cases like that of Florence, this led to the creation
of a republic and eventually the rise to power of merchant families like the
Medici.

This class conflict helped to lead to some of the
artistic achievements of the Renaissance as well.  Some members of the merchant class
patronized the arts as a way of showing their wealth and asserting their right to be
more important in society.  By doing so, they helped to promote the arts that are so
identified with the Italian Renaissance.