It wasn't "defeated by republicans" it was declared by the bourgeoisie. Both parties are sockpuppets for capital's interests. If the democrats were to fight at all it would only be in a situation where their defeat is ensured so as to appear to be for our interests yet never actually are.
Phrasing this as it is now is nothing but "red team blue team" politics and perpetuates the charade of bourgeois democracy.