Ah but I'm not arguing that this dispute is religious in nature or that religious people all agree (the bible has nothing to say on the topic of mass immigration anyway, AFAIK).
Rather that the people protesting for or against something because of their religious views are much less likely to suddenly change those views or crumble in the face of pressure from opposing activists. They have some sort of concrete belief system that they've thought about and are invested in - it doesn't have to make sense, but they aren't going to turn around and say, "ok ok I promise I won't be pro-life anymore" because some angry Google engineers tweeted that they must hate women's rights. Their views are more robustly grounded than that.
Rather that the people protesting for or against something because of their religious views are much less likely to suddenly change those views or crumble in the face of pressure from opposing activists. They have some sort of concrete belief system that they've thought about and are invested in - it doesn't have to make sense, but they aren't going to turn around and say, "ok ok I promise I won't be pro-life anymore" because some angry Google engineers tweeted that they must hate women's rights. Their views are more robustly grounded than that.