All things being the same I think mass immigration does lower inflation. It seems quite straightforward in one respect: if the supply of workers is increased, wages do go down. The way things are today though; inflation may be the least of our worries. These days I worry more about deflation.
Science and technological developments, which spur productivity, also pressure inflation downward. In fact, that is where our emphasis as a country should always be. Technology solves old problems, creates new efficiencies, saves money etc. Not to mention it's keeps us on the frontier of science and discovery where good things flow. And machines over time replace unskilled manual labor.
But like you previously mentioned, the social tax on America for the array of welfare services we provide to new immigrants (many of which are illegal) are a cost that few in Washington want to talk about. These costs are so great that it is hard to see where the net effect of mass immigration is anything but negative for America. To say nothing of how our culture, the families that actually built this country, are being rapidly displaced with 3rd world peoples that come from countries where tyranny is the norm and corruption is a way of life. I can’t see how this can be anything but a disaster for America.
With quite a few businesses, cheap labor just means higher profits for the CEOs, which amounts to corporate welfare.
Bingo. That really is the power behind the immigration free of all in this country. All the talk about immigration producing lower inflation is just a weak rationale for taking what are really bribes from businesses to keep America on its insane immigration ride.