This is not true. Very many things in this country are owned by entities that are not citizens -- foreign corporations and/or foreign individuals.
> and stand to make a bit of cash if there's an influx of new faces looking to buy houses, used cars, rent rooms, etc etc etc.
Sure, some people (some of whom are citizens) own things for which local demand and prices would increase with an influx of new people. Lots of citizens don't own much, and would be competing to purchase those things, and would suffer rather than benefit from the higher prices.
The benefit here is pretty much directly in proportion to current ownership of capital (just like the benefit from greater supply, and therefore lower prices, from labor.)