WASHINGTON - Landmark legislation to secure U.S. borders and offer millions of illegal immigrants a share of the American dream cleared the Senate on Thursday, a rare election-year reach across party lines and a triumph for President Bush.

The 62-36 vote cleared the way for arduous summertime compromise talks with the House on its immigration measure focusing on border enforcement with no guarantee of success. Republicans and Democrats said energetic participation by Bush would be critical.

"Why not say to those undocumented workers who are working the jobs that the rest of us refuse, come out from the shadows," said Arizona Republican John McCain, a key architect of the bill.

The legislation includes money to better secure the borders, provide a new guest worker program and give an eventual shot at citizenship to many of the estimated 11 million to 12 million immigrants in the country illegally.

The bill "strengthens our security and reflects our humanity," said Edward M. Kennedy, D-Mass., McCain's partner in the Senate compromise. "It is intended to keep out those who would harm us and welcome those who contribute to our country."

Majority Leader Bill Frist, R-Tenn., and the Democratic leader, Harry Reid of Nevada, both sided with supporters, a reflection of the bipartisan backing for a bill that was months in the drafting and survived several near-death experiences. In all, 38 Democrats, 23 Republicans and one independent voted for the bill, while 32 Republicans opposed and four Democrats opposed it.

Conservative critics attacked the legislation to the end after trying unsuccessfully to pull it apart with amendments.

"This bill will not secure our borders," said Sen. Jeff Sessions, R-Ala., one of the most persistent critics.

"This is amnesty," added David Vitter, R-La., who tried last week to strip out provisions relating to citizenship.

Not so, said Sen. Arlen Specter, R-Pa., chairman of the Judiciary Committee, in a rebuttal to weeks of debate. "They have to pay a fine. They have to undergo a criminal background check. They have to pay back taxes, they have to learn English and they have to go to the back of the line," he said, referring to illegal immigrants who would apply for citizenship.

Still, Sessions, Vitter, John Cornyn of Texas and others echoed a view widely held among House Republicans, many of whom have vigorously denounced the Senate bill as well as Bush's call for a "comprehensive approach" to the issue.

That portended difficult compromise talks in the shadow of midterm elections, at a time when Bush's poll ratings are low, congressional Republicans are concerned and Democrats are increasingly optimistic about their chances in November.

Lawmakers in both parties pledged strenuous efforts to reach a compromise. Specter said that Republicans, as the party in power in Congress and the White House, had a special burden to produce a compromise. "I believe the president will put a heavy shoulder to the wheel," he added.

Internal GOP divisions will complicate compromise talks. In the Senate alone, four members of the leadership voted against the bill, including Sen. Elizabeth Dole of North Carolina, chairman of the party's senatorial committee.

House Majority Leader John Boehner, R-Ohio, issued a statement that said, "we owe it to the American people to seek common ground on responsible solutions, while always stressing our most important priority is to secure our borders and stop illegal immigration."

The House bill, which passed on a largely party-line vote last year, is generally limited to border enforcement. It would make all illegal immigrants subject to felony charges and it contains no provision for either a new temporary worker program or citizenship for men, women and children in the country unlawfully.

In contrast, the Senate bill would mark the most far-reaching changes in immigration law in two decades.

Built on compromise after painstaking compromise, it was designed to appeal to conservatives and others seeking tougher border enforcement; business interests eager for a steady supply of legal, low-wage labor; unions seeking enhanced protections for migrants who often toil in seasonal work the fields and Hispanics who are on the cusp of greater political power and determined to win a change in legal status for millions of illegal immigrants.

That last group - Hispanics - comprises the fastest growing segment of the electorate, and millions made their feelings clear in street demonstrations denouncing the House measure and calling for passage of a broader measure.

Bush played a prominent role in the run-up to passage. An Oval Office speech last week made explicit his support for the Senate's overall approach. A later trip to Arizona was designed to reassure conservatives about his commitment to stanching illegal immigration.

In more than a week of debate, the Senate made a series of changes in the legislation. Still, the key pillars were preserved when opponents failed to knock out the guest worker program or the citizenship provisions. A new program for 1.5 million temporary agricultural workers also survived.

To secure the borders, the measure calls for the hiring of an additional 1,000 new Border Patrol agents this year and 14,000 by 2011, and backs Bush's plan for a short-term deployment of National Guard troops to states along the Mexican Border. The bill calls for new surveillance equipment as well as the construction of 370 miles of triple-layered fencing and 500 miles of vehicle barriers.

The new guest worker program would admit 200,000 individuals a year. Once here, they would be permitted for the first time to petition on their own for a green card that confers legal permanent residency, a provision designed to reduce the potential for exploitation by employers.

A separate new program, a compromise between growers and unions, envisions admission of an estimated 1.5 million immigrant farm workers who may also apply for permanent residency

Even supporters of the bill conceded the three-tiered program related to illegal immigrants was complicated.

Those in the country unlawfully for five years or more would be permitted to remain, continue working and eventually apply for citizenship. They would be required to pay at least $3,250 in fines and fees, settle any back taxes and learn English.

Illegal immigrants in the country for more than two years but less than five would be required to travel to a point of entry before re-entering the United States legally and beginning a lengthy process of seeking citizenship. They would be subject to the same fines, fees and other requirements as the longer-term immigrants.

An immigrant in the country illegally for less than two years would be required to leave with no guarantee of return.