Cliques will always happen - just as a sorority is a "clique" within the university community, cliques within the sorority will occur.

IMHO, it only becomes a problem when those in the cliques forget their vows of sisterhood, and begin to treat others differently. If you are kind to everyone, then no-one can fault you for who you hang out with.

The other time cliques become a problem is when a power structure gets in place that affects chapter votes. Voting for an officer or a party or a procedure because of another person, and not because you are considering the best interest of the sorority, will lead to the chapter's downfall!

Those are my 2 cents. (am also in a large chapter - 150+ actives)