I love immigrants.  But I don’t mind declining immigration when it’s driven by catch-up growth.  Here’s the NYT on what happened in Mexico over the last decade:

Per capita gross domestic product and family income have each jumped
more than 45 percent since 2000, according to one prominent economist,
Roberto Newell. Despite all the depictions of Mexico as “nearly a
failed state,” he argued, “the conventional wisdom is wrong.”

More:

Over the past 15 years, this country once defined by poverty and
beaches has progressed politically and economically in ways rarely
acknowledged by Americans debating immigration. Even far from the
coasts or the manufacturing sector at the border, democracy is better
established, incomes have generally risen and poverty has declined.

Many forces are at work, but clearly Mexican progress has a big effect on Mexican immigration:

Douglas S. Massey, co-director of the Mexican Migration Project at
Princeton…
said that interest in heading to the United States
for the first time had fallen to its lowest level since at least the
1950s. “No one wants to hear it, but the flow has already stopped,” Mr.
Massey said, referring to illegal traffic. “For the first time in 60
years, the net traffic has gone to zero and is probably a little bit
negative.”

More:

American census figures analyzed by the nonpartisan Pew Hispanic
Center also show that the illegal Mexican population in the United
States has shrunk and that fewer than 100,000 illegal border-crossers
and visa-violators from Mexico settled in the United States in 2010,
down from about 525,000 annually from 2000 to 2004.

Final thought: Realistically speaking, Mexican progress is the only plausible path to an open border.  Once their GDP is half of ours, few Mexicans will want to immigrate, and Americans will magnanimously acquiesce.  Maybe.

HT: Tyler