largest groups happy, poor overall rating?

My largest population sectors are Patriot, Environmentalist, Capitalist, Middle Income, Drinkers and State Employees. All of them are more than 40% populated and more than 60% happy. All other sectors are tiny, or happy.
Why is my overall approval rating so low? 14%?
My largest unhappy group is the Poor, at 27% population and 0 happiness, but anything I do to make them happy is going to upset my larger supporters, so helping them will only hurt my overall numbers, right? Or are happiness values weighted more at the extremes. Does a small number of 0%-happiness pull down more than a large number of 70%-happiness?
I don’t see how I could improve my rating. There are no large unhappy groups to target. All my happy groups are large, and my unhappy groups are small. I must be missing something fundamental; It feels like re-election is impossible.

Yep, so I failed the election miserably. All of those groups that said they were happy voted for the other party. The environmentalists were nearly 80% satisfied with my performance, but only 16% voted for me?

I understand that members of each group are also members of several other groups, but I thought the group populations was the best representation of averages. My strategy was to choose the groups with the largest populations,measure the majority, and make them happy; but that was wrong. What is the right way to measure and identify the majority?