The stability and symmetry breaking bifurcation of a planar liquid drop is studied using the energy-Casimir method and singularity theory. It is shown that a rigidly rotating circular drop of radius
r with surface tension coefficient

and angular velocity

is stable if
2 < 3
. A new brance of stable rididly rotating equilibria invariant under rotation through

and reflection across two axes bifurcates from the branch of circular solutions when
(
)2 = 3