Here are some relevant numbers, from the Center for Immigration Studies.

We no longer have a de jure national-origins quota system for immigrants. In actual practice, though, if you include our lax attitude towards illegal immigration as part of the practice, we have a massive de facto national-origins bias in our immigration. From that link:

Table 4 shows the distribution of immigrants by region of the world, with Mexico and Canada treated separately. Mexico accounts for 31 percent of all immigrants, with 10.8 million immigrants living in United States, more than the number of immigrants from any other region of the world. Immigrants from Mexico, Central and South America, and the Caribbean account for the majority of immigrants, with 54 percent of the foreign‑born coming from these areas. … The importance of the Western Hemisphere, excluding Canada, is even more striking when we look at recent arrivals. Of those who arrived 2000 to 2005, 58 percent are from Latin America.
…One of the striking things about contemporary immigration is that there has been a significant decline in the diversity of immigrants; Mexico accounted for 31 percent of all immigrants in 2005, up from 28 percent in 2000, 22 percent in 1990, and 16 percent in 1980. The top sending country in 1970 was Italy, which accounted for only 10 percent of the foreign-born.

In view of these numbers, it seems to me that a fair riposte to those like Linda Chavez and Geraldo Rivera who accuse their opponents of anti-Hispanic bigotry, would be to ask why they favor the current practice of colossal favoritism towards Latin American immigrants.

Several billion people live in nations poorer than Mexico. E.g. GDP per capita in Ethiopia is $1,000, vs. Mexico $10,600. Don’t those people deserve a shot at the American dream? Where is our generosity? Where is our compassion?