Then why the switch from mayor to councillor? Why not just drop out entirely and focus on your health? City Councillor - that is a busy, busy job. You communicate directly with the people in your ward and take all kinds of meetings.
Well, in practice, he basically spent his entire term as mayor as a city councillor. Spending all his time "fixing pot holes", and such.
Now he can go back to yelling and screaming at every council meeting without actually causing political gridlock.