If that were true, republicans in the U.S. might start being way more OK with abortions. It would be a way to prescreen out the competition.
Seriously, I can see how it would be possible, but not
necessarily because of "heightened rationality." It could also have something to do with need, and what party would be most likely to fill the needs that one has, or the needs that one has been made aware of in one's own life or in the lives of others. (Example: I prohbably wouldn't care much about health care if I'd been perfectly healthy my whole life/I hadn't seen others need it.) It could also have something to do with the demographics/personality variables involved in using the internet, in admitting that one is on the autistic spectrum, etc. etc. But I have no idea.