  We prove the orbital stability of soliton solutions for 2D Maxwell--Lorentz
system with extended charged particle. The solitons corresponds to the uniform
motion and rotation of the particle.
  We reduce the corresponding Hamilton system by the canonical transformation
via transition to a comoving frame. The solitons are the critical points of the
reduced Hamiltonian. The key point of the proof is a lower bound for the
Hamiltonian.
