Statistical physicists have become interested in models of collective social behavior
such as opinion formation, where individuals change their inherently preferred
opinion if their friends disagree. Real preferences often depend on regional cultural
differences, which we model here as a spatial gradient g in the initial opinion. The
gradient does not only add reality to the model. It can also reveal that opinion
clusters in two dimensions are typically in the standard (i.e., independent)
percolation universality class, thus settling a recent controversy about a nonconsensus
model. However, using analytical and numerical tools, we also present a
model where the width of the transition between opinions scales !g{1=4, not
!g{4=7 as in independent percolation, and the cluster size distribution is
consistent with first-order percolation.