Many thanks to Udolpho for pointing the way to the quite hilarious evisceration of Bryan Caplan in his own comments section. I have no idea who Tino is, but I'm a little bit in love. I would urge you to read all of Tino's remarks, but if you're in a hurry, just focus on his first comment, the third one down (no permalink, sorry).
p.s. my favorite line from Udolpho's post: "Instead of debate there is, on the one side, immigration skeptics pointing to demographic trends, class and social realities, and a sea of worrisome data, and on the other side a bunch of deluded pseudo-hippies shouting catchphrases: "YOU CAN'T PUT AN ARMY ON THE BORDER, YOU CAN'T DEPORT THEM ALL, THEY DO THE WORK AMERICANS WON'T DO.""
UPDATE: From another comments thread, I really liked this remark, from Steve Burton: "Those who support open borders like to point out that, in the past, the U.S. has successfully assimilated all sorts of ethnically distinct immigrants.
But the great waves of American immigration in the 19th and early 20th centuries swept ashore in a relatively harsh, sink-or-swim society where one had little choice but to fit in, and to make one's own way.
The Latin American immigrants of today, on the other hand, show up in an advanced welfare state which positively *encourages* them to maintain and to exploit their separate ethnic identity for political and economic advantage.
That's a whole different ballgame."
FURTHER UPDATE: Just to avoid any confusion, I am not the 'adrian' from those comment threads.