Power in the aged is referring to the massive power that the group holds. Well potential power. I may be wrong but this is my thought. The aged make up a big percentage of the population and if they all got together they could overthrow everything. They just don't realise what big numbers they actually have and so they don't act together. The aged is a potentially powerful group as seen in the new a month ago when a large group of the aged population got together to protest some new law. They got it overturned. It think they are starting to realise how much power they actually have. Oh and in places like china and that, respect your elders is one of the main beliefs so therefore they have a lot of power there.
That's my input.
Laters