Thucy,

If that's their stated opinion, then sure, that's cynical. But most likely, you're imposing that view on them. They may not consider their situation "enslavement," they may even understand that they're free, and they may genuinely believe in the principles of the party that promises them less, directly. It is not cynical then to vote as they believe right.

You, on the other hand, would look at somebody's income, do a back-of-the-envelope calculation, and then assume that they "should" vote for whoever will give them the most. In application both to the rich and the poor, that is cynical.