And I certainly don't believe that intelligence is the only, or even a particularly significant, factor in determining people's income or employment status, which is why I take issue with this proposition:
people who are apolitical are also likely to have lower education levels and income levels than people who are politically active, so there is more evidence than JUST IQ that they are less intelligent on average.
We know that, whatever effect IQ may have on people's education levels and income levels, other factors certainly play a part, too -- we know that, along with other factors, which part of the country they live in, their age, state of health, their gender, and their race all play a role in determining people's levels of education and their income levels.
So why do you take the likelihood that people's lower education levels and income as evidence of their intelligence, or lack of it, as opposed to any other factors?
Have you considered, for example, the possibility that someone struggling to make ends meet through a series of dead-end jobs probably doesn't see much point in bothering about politics too much, since she probably has much more immediate concerns to worry about?