During last night's Republican presidential debate, MSNBC aired an ad from a group called Californians for Population Stabilization (CAPS), which the Southern Poverty Law Center has identified as part of an anti-immigration network that includes several organizations it labels “hate groups.”

The CAPS ad shows a man shuffling around the letters of the word “illegal” while saying:

Now that so many Californians are out of work, attention is turning to the millions of illegal workers in the state. It's about time. But what about these workers? Legal foreign workers -- 1 million legal immigrants and temporary workers our government admits every year that take good jobs in places like California, no matter how many Californians are out of work or how ill the economy gets. We need to slow legal immigration 'till California is working again. Paid for by Californians for Population Stabilization.

In a press release announcing the TV ad campaign, CAPS stated:

More legal immigrants reside and settle in California permanently than in any other state. The flow of workers has not stopped since the recession hit. The policy is having a particularly insidious effect in states like California, with millions unable to find a job and unemployment rates topping 18%. As a result, California has been forced to borrow $40 million a day from the federal government to pay unemployment benefits. At the same time, the Federal government continues to flood California with legal immigrants and temporary workers with no calls for an end to foreign workers in sight.

This is a classic appeal to anti-immigrant sentiment: Immigrants “take good jobs,” presumably from native-born Americans. But on the whole, that's not true.

As the nonpartisan Immigration Policy Center notes, immigrants and native-born workers “are usually in different job markets, so they don't compete”: They have different levels of education, are employed in different fields, specialize in different tasks, and live in different places. Furthermore, “immigrants actually create jobs as consumers and entrepreneurs,” the center says.

SPLC reported that CAPS has been funded by U.S. Inc., an entity created by John Tanton, the leader of the American anti-immigrant movement. In addition, CAPS has received funding from the Pioneer Fund, which the SPLC lists as a “hate group.” The SPLC says the fund “has bankrolled many of the leading Anglo-American race scientists of the last several decades.”

The Anti-Defamation League also describes CAPS as an “anti-immigrant group.” The ADL further writes that "[o]ne of its more vocal members, Rick Oltman, is a former FAIR Field Representative who spoke at a gathering of the border vigilante Minutemen group and has also had reported ties to the Council of Conservative Citizens," a white supremacist group.

This raises a question: MSNBC has repeatedly refused to air ads that it deems “controversial.” So given that prominent groups have warned that CAPS spreads an anti-immigrant message, why is MSNBC accepting its money?