We present results of opinion dynamics simulations based on the emotion/information/opinion (E/I/O) model, applied to a strongly polarized society. Under certain conditions the model leads to metastable coexistence of two subcommunities (supporting each of the opinions) of comparable size -- which corresponds to bipartisan split found in many real world communities. Spurred by the recent breakdown of such system, which existed in Poland for over 9 years, we extend the model by allowing a third opinion. We show that if the propaganda messages of the two incumbent parties differ in emotional tone, the system may be "invaded" by a newcomer third party very quickly -- in qualitative agreement with the actual political situation in Poland in 2015.