Well, don't count on it.
Since the bottom half of society breeds at a faster rate, (even with their non-breeding segments) the quality of the average voter declines with each passing year.
That seems a static view of a stratified society with no mobiity. The problem is the wealth of the society. Where the poor are truly poor they do not vote much. Where the poor are actually a leisure class they are more susceptible to being used for their votes and more apt to try to vote themselces a living.