Does democracy really work?

We consider here simple models for opinion changes among a population, which is assumed of fixed size. People are subdivided into two groups, each sharing common ideas. In the first model these two parties interact, by subtracting persons, i.e. ``votes'', to the opposite party. In more refined models, we introduce also the class of ``undecided'' individuals, which may be attracted by the recruiting efforts of either party. We investigate whether and under which conditions the commonly held opinion of ``alternance'' in government is possible.