[NewRomeTacitus]

The Immigration Reform Act of 1965 changed preferences from the well-educated and higher-civilized from countries whose populations happened to be advanced and pale of skin for just the opposite. I believe Evil Ted and his cohorts (under the protective umbrella of Johnson’s “Great Society”) took advantage of the chance to alter the constituency.

[Clemenza]

Actually, the folks who pushed the most for the 1965 immigration act were the "white ethnics" in congress, as said act abolished quotas for eastern Europe and Southern Europe. This is why you saw a huge influx of Greeks and Portuguese into the northeast in the late 1960s-1970s, to say nothing of the Russian Jews who came in droves after Jackson-Vanick was passed.

The fact is, the eastern Europeans are going to places like the UK and France, which are VERY CHEAP to fly to when compared to the U.S. Southern Europeans aren't reproducing, although it seems to me that every wealthy Italian keeps a place in Manhattan or Miami these days (the poor Italians being kept fat by Italy's generous welfare state).

Even if we abolished all visa/residency requirements for Europeans, we wouldn't have a much larger influx than we would now. If we gave preference to the skilled and educated, we would probably see more immigration from Asia, with a very slight uptick from Europe.