Although the Center for Immigration Studies (CIS) bills itself as an "independent" think tank that seeks "to expand the base of public knowledge" about immigration, the Washington, D.C.-based group is only interested in one thing. CIS's reams of reports, as well as its blog postings, editorials, and frequent panels and press conferences, incessantly push the idea that America's immigration system is an unadulterated evil and that the only way to save America from impending doom is to cut drastically the number of immigrants. CIS has blamed immigrants, both legal and undocumented, for everything from terrorism to global warming. To make its case seem as strong as possible, CIS often manipulates data, relying on shaky statistics or faulty logic to come to the preordained conclusion that immigration is bad for this country. But CIS studies have been regularly debunked by mainstream academics and think tanks including the Immigration Policy Center, the Center for Budget and Policy Priorities and America's Voice. Here are some examples:

"Hello, I Love You, Won't You Tell Me Your Name: Inside the Green Card Marriage Phenomenon" (November 2008). This report alleges widespread fraud among marriages between American citizens and foreigners, but then goes on to admit that "there is no way of knowing" just how prevalent marriage fraud is because there is no systematic data. CIS even concedes that most marriages "between Americans and foreign nationals are legitimate." Then, based on this non-data, CIS gets to what seems to be the real point of its study — "if small-time con artists and Third-World gold-diggers can obtain green cards with so little resistance, then surely terrorists can." Fraudulent marriage applications, CIS concludes, are "prevalent among international terrorists, including members of Al-Qaeda."

"Homeward Bound: Recent Immigration Enforcement and the Decline in the Illegal Alien Population" (July 2008). Widely cited by the mainstream press, this report argues that the migration decisions of undocumented workers are based more on the level of immigration enforcement than the lure of jobs. In other words, as CIS argues, the Bush Administration's stepped-up enforcement efforts in 2007 were working, leading to an exodus of undocumented workers. But experts said the decreases in the undocumented population that the report claims to have documented were not mainly the result of enforcement efforts. Wayne Cornelius, director of the Center for Comparative Immigration Studies at the University of California-San Diego, said that "undocumented migration clearly responds to changing U.S. economic conditions" more than anything else. The report also suggests, without any supporting evidence, that undocumented workers may have decided to stay here longer than they would have otherwise because of the 2007 immigration debate.

"Employment Down Among Natives in Georgia: As Immigrant Workers Increased, Native Employment Declined in Georgia" (June 2007). Focusing on Georgia between 2000 and 2006, this report argues that an increase in less educated immigrant workers caused employment to decline among less educated natives. But if offers no direct evidence to support that conclusion, and most other studies have reached very different conclusions. A study by Jeffrey Humphreys, director of the Selig Center for Economic Growth at the University of Georgia, concluded that during the period of highest immigration in Georgia, starting in 1996, jobless levels among native-born workers remained very low. He also found that in sectors where less educated immigrants are concentrated, such as construction, immigration made it possible for "the industry to expand rapidly," and said that the increased size of the work force led to improved benefits for all workers. Many other studies concur that immigration is generally good for the economy. In 2007, for instance, the Public Policy Institute of California found that immigrants arriving in that state between 1990 and 2004 increased native-born workers' wages by an average 4%, because immigrants mainly performed complementary, not competitive work, that helped the economy grow.

"Back Where We Started: An Examination of Trends in Immigrant Welfare Use Since Welfare Reform" (March 2003). This report argues that after declining in the 1990s, immigrants have made up "a growing share of all households using the welfare system" — in other words, they have been sapping public benefits. But the month after it was released, the study was thoroughly debunked by the Center on Budget and Policy Priorities (CBPP), which said CIS had manipulated data. First of all, CIS included as immigrant households even those headed by naturalized citizens and it also attributed "benefit use to an immigrant household in cases where the only members of the household receiving benefits are U.S. citizens." CBPP pointed out that the CIS study itself found that use of Temporary Assistance to Needy Families, Supplemental Security Income and food stamps by these households had declined substantially between 1996 and 2001, but "because it finds that the share of such households with at least one member who receives Medicaid rose modestly," it concludes "that the share of immigrant households using 'at least one major welfare program' has not declined since 1996." The CIS report "fails to mention that the modest increase in Medicaid participation by so-called 'immigrant' households is due entirely to an increase in Medicaid or State Children's Health Insurance Program (SCHIP) use by U.S. citizens who live in households headed by foreign-born individuals." "CIS inexcusably fails to disclose," says CBPP, that "among both noncitizen adults and noncitizen children, Medicaid participation declined between 1996 and 2001." Even worse, the CBPP report, "using the same database as CIS," found that "the percentage of legal noncitizens participating in each of the major means-tested federal programs ...declined significantly since 1996."