  We analyze the existence and stability of dynamical attractor solutions for
cosmological inflation driven by the coupling between fermions and a gauge
field. Assuming a spatially homogeneous and isotropic gauge field and fermion
current, the interacting fermion equation of motion reduces to that of a free
fermion up to a phase shift. Consistency of the model is ensured via the
Stuckelberg mechanism. We prove the existence of exactly one stable solution,
and demonstrate the stability numerically. Inflation arises without fine
tuning, and does not require postulating any effective potential or
non-standard coupling.
