From this:

Looking to capitalize on the growing remittance industry, largely fueled by illegal aliens sending money earned through illegal employment in this country, back home, the U.S. Post Office now offers a wire transfer service, but only to countries in Latin America.

The service, called Dinero Seguro (Sure Money) is being advertised in local post offices with posters showing a Latino family, along with the caption "for your wire transfer of funds back home."

He called their customer service line and was told that one acceptable form of identification was a Matricula Consular card, a virtual guarantee that the bearer is an illegal alien.

What that boils down to is that the US Postal Service has a financial stake in illegal immigration: the more illegal immigration, the more money they'll make. Needless to say, giving the federal government a profit motivation to support or ignore illegal activity is very dangerous and leads to political corruption.