Byron York

When left-leaning activist groups, civil rights leaders and lawmakers in several cities called for a boycott of Arizona's new illegal immigration law, they did more than make a point about illegal immigration. They also set off a war -- a war that no one will win.

The boycott movement started when Arizona Democratic Rep. Raul Grijalva urged businesses and other organizations to cancel conventions and conferences in his home state, where tourism is a big part of the economy. Things picked up steam when San Francisco and Los Angeles threatened to go beyond banning employee travel to Arizona and considered a boycott of virtually all business with the state. Then the activist groups, among them the Service Employees International Union, National Council of La Raza and the Leadership Conference on Civil and Human Rights, urged the same thing: a total economic boycott of Arizona.

Michelle Malkin

Now Los Angeles has followed up on its threat, passing a boycott measure that could affect about $8 million in city business with Arizona. Other cities are considering similar moves.

What if that happens? In addition to tourism, Arizona is a major presence in the construction, health care, manufacturing and aerospace industries. What if some cities, or even entire states, canceled their business with Arizona-based companies?

"It doesn't take a rocket scientist to know that if that started, at any level, there would be reciprocation from Arizona," says Barry Broome, president of the Greater Phoenix Economic Council. "A boycott can only lead to harm."

It's a pretty simple situation. Lots of cities in California, for instance, do business with Arizona-based companies. But Arizona also does business with lots of California-based companies. "How many Los Angeles- and San Francisco-based companies are doing hundreds of millions of dollars of work in Arizona?" Broome asks. "We have a huge construction and public works platform."

If a city cuts off business in Arizona, then Arizona could find itself forced to do the same thing. The result would be insanity -- a trade war inside the United States, all over a law legitimately passed by the Arizona state legislature, signed by the governor and supported by a majority of its people.

Even Grijalva seems to understand that. Everybody knows that Hispanic-American families would be among those hurt by a boycott of Arizona. During a recent Washington Post web chat, Grijalva became defensive when a reader asked him to reconsider his stance because a boycott could "hurt the people who need help and support the most."

Byron York

Byron York, chief political correspondent for The Washington Examiner