Simmiah, regarding your question:
Yes, not only does it depend on the wording of the statements, but more importantly it depends on what is held in mind when calibrating, and that usually has a very wide disparity so these calibrations must be taken with a grain of salt and common sense. The Doc himself had been calibrating for over 20 years when he realized that he got different calibrations when accidentally holding in mind different things, i.e. an African elephant vs. a circus elephant.
More specifically about the voting question, my intuition tells me that you've got it right: the calibration of "people who do not vote" is just an averaging of the consciousness mindset in that particular situation, i.e. when people think about not voting they usually think that it's too bothersome, or that it won't change the results anyway, etc., as opposed to the mindset of people who do vote would usually calibrate over 200+ just by being proactive. Thus it doesn't say anything about the people individually or even in aggregate, but just the consciousness level of people in that particular "situation".