  We analyze a continuous time multidimensional opinion model where agents have
heterogeneous but symmetric and compactly supported interaction functions. We
consider Filippov solutions of the resulting dynamics and show strong Lyapunov
stability of all equilibria in the relative interior of the set of equilibria.
We investigate robustness of equilibria when a new agent with arbitrarily small
weight is introduced to the system in equilibrium. Assuming the interaction
functions to be indicators, we provide a necessary condition and a sufficient
condition for robustness of the equilibria. Our necessary condition coincides
with the necessary and sufficient condition obtained by Blondel et al. for one
dimensional opinions.
