One of the common arguments supporters of massive illegal immigration use is "They're just coming to work."

Obviously, millions of people are "just coming here to work", and a significant portion of the world's population would also like to "just come here to work".

If there were only a small number of illegal aliens in the U.S., this wouldn't be such an issue. However, when you start talking about millions of people, it becomes a much larger issue of policy and it has an extremely serious impact on our labor market, our infrastructure, and our society. Anyone who uses this argument is unable to understand that, or is being disingenuous and trying to fool you into thinking that we aren't talking about a major impact on our society and markets.

In addition, not all who come here are working. While the head of a family might just be coming here to work, his wife might not be working, and his children might be attending public schools. And, elderly family members might not be working either.

And, some illegal aliens might not be coming to work, but to be part of criminal organizations, gangs or have even more nefarious goals.

If we're going to consider this a valid argument, where does it end? How many millions more must we let in? We're either going to let anyone come here at any time, or we're going to have some kind of a limit. That latter limit is called our immigration laws.

There's also the issue of where these workers are coming from. Is it good to allow millions of people from one country to move in to the U.S.? As will be discussed later, that gives Mexico political power inside our country and is a grave threat to our political system.

And, just how desirable is low-priced, low-skilled labor? While such (massively subsidized) labor keeps some industries afloat, just how necessary are those industries? Is it better to grow strawberries in the U.S., or is it better to import them rather than importing people to pick them? And, wouldn't the best approach be developing automated methods to growing products such as strawberries?

Used by all parties: the GOP, the Dems, the media, and so on.