June 12 (Bloomberg) -- Most Americans support central elements of the legislation overhauling U.S. immigration laws the Senate shelved last week after it failed to gain sufficient support from lawmakers.

A new Bloomberg/Los Angeles Times poll shows that at least a plurality of Americans backs the two most contentious provisions of the bill, a proposal to offer 12 million undocumented immigrants a path to citizenship and the creation of a guest- worker program. Of a third provision -- a point system for immigrants based on professional qualifications -- many say they don't have enough information to have an opinion.

Moreover, most of those surveyed appear to reject one of the central arguments deployed by the bill's opponents: The poll found that less than a third of all respondents, including Republicans, believe illegal immigrants take jobs away from Americans who need them.

Still, analysts say opponents have an impact that is disproportionate to their numbers because of the intensity of their feelings and capacity to organize.

``For a minority of people, immigration is the most important issue, and they are the ones who are defining the debate with volatile rhetoric and their activism,'' says Nathan Gonzales, a political editor at the Rothenberg Political Report, a nonpartisan Washington newsletter.

Impact on McCain

Arizona Senator John McCain, a Republican presidential candidate who is among the bill's most ardent supporters, already is paying a political price. The poll shows that he has fallen far behind the party's frontrunners, former New York Mayor Rudy Giuliani and former Tennessee Senator Fred Thompson, who oppose the legislation. Among Republicans who say immigration is the most important issue in the election, McCain, 70, gets just 1 percent of the vote.

In general, those surveyed are sour about the way the country is going. The poll found the percentage of Americans who say the nation is on the wrong track increased 3 points, within the poll's margin of error, to 69 percent, compared with a poll taken in April. Even half of Republicans, 51 percent, say the country is on the wrong track.

The poll also shows a slight decline in President George W. Bush's approval rating to 34 percent, a record low for the survey, from 36 percent in April. The survey of 1,183 adults nationwide was conducted June 7 to 10 and has a margin of sampling error of 3 percentage points.

Bush and Iraq

On Iraq, the number of people who disapprove of Bush's handling of the war remains steady, at 67 percent, compared with 65 percent two months ago.

The poll shows bipartisan support for setting benchmarks for improvement in Iraq and withdrawing U.S. troops if the Iraqi government fails to meet those goals. Almost three-fifths of Republicans and self-described conservatives support setting benchmarks, along with 74 percent of Democrats and 62 percent of independents.

That bipartisanship disappears when it comes to setting a timetable for withdrawal. Overall, more than half of Americans support such a measure, including 60 percent of independents, 82 percent of Democrats, and just 24 percent of Republicans.

Withdrawal Timetable

``If we set a timetable there may be more possibility for things going awry; I think we should go into it with some flexibility,'' says Brent Bartlett, a 19-year-old student at Emory University in Atlanta who describes himself as a moderate Republican.

The poll also shows a small increase over the past five months in the percentage of Americans who want an immediate withdrawal of U.S. troops. In January, 19 percent of Americans wanted an immediate withdrawal, while 25 percent now say they do.

Poll respondents say Iraq is a central issue in the presidential elections, though 86 percent pointed to illegal immigration as an important problem facing the nation. Still, more than half of those surveyed, 56 percent, say immigrants take jobs that no American wants.

``People are living in a dreamland if they think our economy can survive without these people,'' says Paul Evans, a 52-year- old Republican. Evans, a retired Marine officer and pilot, lives in Etowah, North Carolina, a rural part of the state where many apple orchards employ immigrant workers.

The poll also suggests Congress may have to work harder to educate Americans on legislation it is considering. Senate Majority Leader Harry Reid of Nevada -- who pulled the measure last week after he was unable to garner enough support to bring it to a vote in the closely divided chamber -- said June 8 that he would consider reviving it ``as soon as enough Republicans are ready to join us.''

Kathryne Bussey, a 64-year-old retired accountant from Ada, Michigan, says she is concerned about illegal immigration and wants Congress to act. ``Truthfully, I don't know if I understand the bill,'' says Bussey, a Republican.

To contact the reporter on this story: Heidi Przybyla in Washington at hprzybyla@bloomberg.net

Last Updated: June 12, 2007 17:01 EDT