Jason DeParle of the New York Times almost follows the money on Western Union, a company that makes almost a billion dollars per year off legal and illegal immigrants sending money home ("remittances"): link. While it's a much better job than, for instance, Jill Capuzzo of that paper would have done, he doesn't go as far as he could. However, he does uncover some interesting contributions they've made:

The company sponsored public forums to promote ["comprehensive immigration reform"] and donated $100,000 to a group unsuccessfully fighting Proposition 200 in Arizona, which requires proof of citizenship from people seeking to vote or collect certain public benefits.

As the debate moved to Washington, Western Union gave money to many groups supporting legalization plans. The United States Chamber of Commerce received "in the high six figures," a Chamber official said, while an Illinois group [perhaps the Mexico-linked Illinois Coalition for Immigrant and Refugee Rights; see this] used some Western Union money to bring busloads of immigrants to Capitol Hill. When a bipartisan Senate bill emerged last spring, company officials flew to Washington to lobby directly, urging Senator Ken Salazar, a Colorado Democrat, to support the measure. He did, though it ultimately failed.

"Most companies are afraid to speak up," said Frank Sharry, executive director of the National Immigration Forum, which has received $40,000 from Western Union in the past three years. "When it got hot, they stayed with it."

And, more sleaze practically drips from the page:

Many of his customers are in the country illegally. [Michael Lee, 35, who owns an electronics store called World Top Communications in New York’s Chinatown], who was once an illegal immigrant, said his business fell by about 40 percent last spring after a series of nationwide immigration raids...

Salo Eduardo Levy, Western Union's Mexico director, echoed that theme at a September meeting of industry executives. "We have customers calling agents before they go: 'Is it safe? Is La Migra around?'"

A 2006 survey by the Inter-American Development Bank found that illegal immigrants made up 41 percent of the Latin Americans in the United States who used money transfer companies.

[...in 1999 they held promotions in front of a U.S. detention center for illegal aliens and held events in Central America for those deported from the U.S...]

...["former company official who spoke only on the condition of anonymity" says:] "We knew that within a week they would be back on their way to the U.S."

[WU VP Fred Niehaus says they won't do things like that anymore]