Slim and Bill

The world's richest individual may no longer be Bill Gates, but Mexican tycoon Carlos Slim. This Wall Street Journal article is currently free but may eventually go into the pay archive:

The Secrets of the World's Richest Man
Mexico's Carlos Slim makes his billions
the old-fashioned way: monopolies
...
Mr. Slim's strategy has been consistent over his long career: Buy companies on the cheap, whip them into shape, and ruthlessly drive competitors out of business....

His control of Mexico's telephone system has slowed the nation's development. While telephones have long been standard in any American home, only about half of Mexican homes have them. Only 4% of Mexicans have broadband access. Mexican consumers and businesses also pay above-average prices for telephone calls, according to the Organization for Cooperation and Economic Development.
...
There is no obvious successor to the patriarch's empire. That gives some Mexican officials hope that one day the state can regulate his companies. Says one high-ranking official: "When Slim dies, we can finally regulate his kids."

I have no problem with this per se.

(In defense of America's cowboy reputation, I assert that if our Mr. Bill were as free to act monopolistically as Carlos Slim is, it would be no contest. Gates is not as free: Microsoft was reined in by the courts.)

Sensible regulation of monopolists presumably benefits our economy. If a titanic illegitimate monopoly damages the Mexican economy, presumably that is no concern of the United States.

However, we are undergoing massive illegal immigration. To what extent is this due to the lack of opportunity in the stifled Mexican economy? Does the situation increase the radical US-unfriendly left's attractiveness to the Mexican electorate?

Is America in effect subsidizing the fortunes of Slim and those like him?