Elite vs. popular opinion on legal immigration: not so complicated

From this:
Here's a puzzle: All nonadvocacy surveys of public opinion show only tiny minorities - commonly about 10 to 20 percent - favoring increased legal immigration. Last month's national survey by the Pew Center for the People and the Press is typical, reporting only 17 percent in this camp.

Yet the two opposing bills that have been roiling the Senate both include little- scrutinized provisions that would greatly increase permanent legal immigration. These survived quietly, largely ignored by politicians and the press, while emotional debate and commentary focused on illegal immigrants and temporary workers...

The most recent [Chicago Council on Foreign Relations 'elites vs. popular opinion' poll], from 2004, shows that 33 percent of the "leaders" group wanted to increase legal immigration, vs. only 11 percent of the public opinion sample. Only 10 percent of the leaders group wanted to decrease the level of legal immigration, while fully 54 percent of the public opinion sample supported such decreases...

...Members of the US Senate - an elite among elites - do seem to be quite insulated from the views that pollsters routinely find among broad public opinion. On this issue senators may be even further disconnected from those who elect them as they are also surrounded by flocks of immigration lobbyists representing small but well-organized and heavily financed interest groups...
It's really not as complicated as it might seem. In fact, I've cleverly annotated the following paragraph from the article in order to help illustrate why Senators and many House members might support massive immigration:
The$e intere$t group$ are regional, economic, ethnic, and ideological. Prominent among them: agribu$ine$$ companie$ in California and the $outhwe$t; employer$ of mo$tly low-wage labor $uch a$ hotel$ and re$taurant$; a few union$ with large percentage$ of immigrant member$; $ome high-tech companie$; $ome ethnic and religiou$ lobby group$; $ome higher education group$; and ideological libertarian$ of both the right and the left.
Yes, that's a pretty ugly paragraph, but so is political corruption.

Related: "Who's responsible for illegal immigration?"