Social scientists make strange survey respondents. I parse questions similarly, but that’s not exactly typical of participants in a poll, survey, focus group, or experiment.

And good point. It would’ve been better to say “it’s possible many use ‘open borders’ as a proxy for increased immigration,” rather than “more likely.” I’ve heard “open borders” used that way, but things I’ve heard ≠ data, and the possibility is sufficient to make the point that the question is ambiguous.