After my last column criticizing Arizona's xenophobic immigration law, I got an avalanche of readers' comments. Most of them were angry anti-immigrant tirades, but some made important points that deserve an answer.

I won't waste your time responding to those that reek of racial prejudice. Instead, I will try to respond to some of the most common criticisms made by intelligent, well-meaning people whose arguments can't be dismissed as coming from the lunatic fringe.

Denise, who describes herself as a "white Anglo who has lived in Miami all my life" and wonders "how much longer I will be able to live in the town I grew up in," writes: "I am already a minority who is discriminated against and often feel that I live in a foreign country because of the huge population of Latins who insist on speaking Spanish."

"My question to you is, Why is it so awful for the citizens of the United States to simply ask immigrants who wish to live in America to do so legally? And why should we reward those who broke the law and came here illegally?" she asks. "Maybe in your next article you can address these questions."

Well, Denise, let me try. There are four major reasons why I take issue with the premise behind your questions.

First, there would be nothing wrong with demanding that immigrants come to the United States legally if we allowed them to do so. But we don't -- they are coming through the back door to take jobs we offer them, because we don't allow them in through the front door. Legal immigration quotas were set more than 20 years ago, when the U.S. demand for unskilled and highly skilled workers was much smaller than today's.

The U.S. labor market demands up to 500,000 low-skilled workers a year, while the current U.S. immigration system allows for only 5,000 permanent visas for that category, according to the National Immigration Forum, a pro-immigration reform advocacy group.

"There is no real line for unskilled workers," says Maurice Belanger, the Forum's public information director. "If you are a Mexican wanting to get a legal visa to work as a waiter in the United States, you would be dead before you get your visa."

It's somewhat easier to immigrate legally if you have close family members who are U.S. citizens, but often not by much. According to the latest U.S. State Department's visa bulletin, there is a lengthy backlog in several family visa application categories.

To read the complete column, visit www.miamiherald.com.