It also boggles the mind that immigrants are the issue while the 1% own as much as the entire middle class, while the bottom class owns nothing at all. When you pay more for groceries, or rent, or gas do you think it's the immigrants making it expensive?
Cost of groceries/gas are a separate issue. Does not mean immigration isn't.
And do you think immigrants do not make rent more expensive? If you increase the demand, without increasing the supply, what do you think happens?
Regardless, immigration can harm the poor by having increased competition for low paying jobs. Bernie Sanders called open borders a Koch brothers plan to get cheap labor.
This is especially true of illegal immigration since they will naturally be paid less because there is a legal risk.