I have canvassed for political candidates who had some position or other that i disagreed with (though never something I disagreed with quite as strongly as this example). I've thought about how I'd answer if someone asked me about that particular thing - someone who shared my view rather than my candidate's. In all of these cases, of course, I had good reason to support the candidate on balance, and very strongly, so I had some good answers that would've been interesting if anyone had asked. In practice, people tend not to ask questions like that when you're canvassing for a candidate, though.