  We study the stability of the critical points of the Onsager energy
functional with Maier-Saupe interaction potential in general dimensions. We
show that the stable critical points must be axisymmetric, which solves a
problem proposed by [H. Wang, P. Hoffman, Commun. Math. Sci. 6 (2008),
949--974] and further conjectured by [P. Degond, A. Frouvelle, J.-G. Liu,
Kinetic and Related Models, 15(2022), 417--465]. The main ingredients of the
proof include a suitable decomposition of the second variation around the
critical points and a detailed analysis of the relation between the intensity
of interaction and the order parameter characterizing the anisotropy of the
solution.
