There is scant evidence that illegal immigrants have caused any significant damage to the wages of American workers.

Hundreds of thousands throng U.S. cities to call for legislation that permits a path to citizenship for many illegal immigrants. It remains to be seen how responsive U.S. lawmakers struggling with a reform bill will be to their demands.

Standard & Poor's answers some of the crucial questions involved in the illegal immigration debate, and discuss its costs and benefits in the most affected states and municipalities along the U.S.-Mexico border.

Estimates of the number of undocumented immigrants remain fuzzy and full of pitfalls, even as lawmakers toss them around in the latest round of debates over whether to offer guest-worker status to illegal immigrants.

This report analyzes the problems of immigration facing the United States, focusing on five specific metropolitain areas.

As the U.S. Senate takes up the controversial issue of immigration, competing Senate proposals offer measures from building walls and increasing border patrol to guest-worker programs and amnesty. But the acrimonious political mood around the issue will make the necessary compromises difficult to reach.

President Bush is in Mexico, where the issue of immigration is likely to dominate the trilateral North American summit. The U.S. Senate is debating proposals ranging from tougher enforcement measures against illegal immigrants to providing them with a path to citizenship.

The U.S. Senate is debating punitive immigration measures as the new federal budget proposes heavy investments in "hardening" America's borders. The issue adds fuel to the election-year fire—particularly in the American southwest—as political passions rise.

This report covers the immigration histories of 94 terrorists who operated in the United States between the early 1990s and 2004, including six of the September 11th hijackers. Other than the hijackers, almost all of these individuals have been indicted or convicted for their crimes. The report builds on prior work done by 9/11 Commission and the Center for Immigration Studies, providing more information than has been previously been made public.

The findings show widespread terrorist violations of immigration laws. The report highlights the danger of our lax immigration system, not just in terms of who is allowed in, but also how terrorists, once in the country, used weaknesses in the system to remain here. The report makes clear that strict enforcement of immigration law – at American consulates overseas, at ports of entry, and within the United States – must be an integral part of our efforts to prevent future attacks on U.S. soil.

According to this report, the outline for transformed border management is clear. It requires a risk management approach to policing cross-border flows which includes the close collaboration of the major beneficiaries of an increasingly open North American continent-our neighbors to the North and the South, and the private sector.