"We all share the desire to alleviate the burdens it has placed on our state and local governments, our business and our citizens. We cannot overstate either the importance of this problem to our States or our desire to see Congress act," the letter states.

In general, the bill is designed to strengthen enforcement of U.S. borders, regulate the flow into the country of so-called guest workers and determine the legal future of the estimated 11 million immigrants living in the United States illegally.

The bill would double the Border Patrol and authorizes a "virtual wall" of unmanned vehicles, cameras and censors to monitor the U.S.-Mexico border.

It also allows more visas for nurses and agriculture workers, and shelters humanitarian organizations from prosecution if they provide non-emergency assistance to illegal residents.

The most controversial provision would permit illegal aliens currently in the country to apply for citizenship without first having to return home, a process that would take at least six years or more. They would have to pay a fine, learn English, study American civics, demonstrate they had paid their taxes and take their place behind other applicants for citizenship, according to aides to Kennedy.

But the committee also stripped the bill of its provisions for criminal penalties for those in the country illegally. Mike Sizer, chairman of Utahns For Immigration Reform and Enforcement, said it was unfortunate that the committee stripped the House's criminal provisions, and added what he sees as amnesty.

"If you are allowed to get citizenship for being here illegally, and it's paying a small fee, or a slap on the wrist, that's an amnesty," Sizer said. "Poll after poll has shown (amnesty) is against what the American public wants."

Timothy Wheelwright, president of the Utah chapter of the American Immigration Lawyers Association, said he hadn't fully reviewed the bill, but "it looks promising."

When compared to the House's approach, Wheelwright said, "It's more realistic in terms of the problem we're actually facing. This is a complex problem that requires a comprehensive solution."

The committee met as several thousand demonstrators rallied at the foot of the Capitol. Many were members of the clergy who donned handcuffs and sang "We Shall Overcome," the unofficial anthem of the civil rights era.

Arizona GOP Sen. John McCain, a potential presidential contender who worked with Kennedy on the issue, told reporters the street demonstrations had made an impact. "All those people who were demonstrating are not here illegally. They are the children and grandchildren" of those who may have been, he added.