WASHINGTON -- Fred Thompson, a potential Republican presidential candidate, suggested that the 1986 immigration law signed by President Ronald Reagan is to blame for the country's illegal immigrants, and he bemoaned a nation beset by "suicidal maniacs."

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"Twelve million illegal immigrants later, we are now living in a nation that is beset by people who are suicidal maniacs and want to kill countless innocent men, women and children around the world," the former Tennessee senator said. "We're sitting here now with essentially open borders."

He made the comments Thursday night as he discussed the 1986 immigration bill and the Senate's current legislation to overhaul the immigration system during a speech to people attending the annual Prescott Bush Awards Dinner in Stamford, Conn.

Thompson, an actor on NBC's popular drama "Law & Order," is widely expected to enter the GOP presidential race this summer. His backers bill him as a conservative in the mold of Ronald Reagan who can beat the Democratic nominee in November 2008.

Immigration has dominated the Republican presidential race this week, with candidates seeking to navigate the tricky politics of the Senate measure that many conservatives oppose. They make up a large part of the GOP base whose votes are critical in the Republican primary contests.

New Legislation Contentious

Lawmakers are bracing for political blowback from liberal and conservative critics of a broad immigration overhaul measure that's on hold as they head home for a weeklong break.

Related: Campaign Coverage | Immigration Coverage

Supporters and opponents said they would use the time off to influence senators who will face major immigration votes when they return to complete the bipartisan measure. The bill would legalize millions of unlawful immigrants, tighten border security and mandate that employers verify they are hiring legal workers.

"As we head into the Memorial Day weekend, members of the Immigration Reform Caucus will go back to their districts and remind their constituents about the long-lasting damage passing an amnesty bill would have on our efforts to address illegal immigration," said Brian Bilbray, R-Calif., a vocal opponent of the measure.

A coalition of organizations actively pressing for passage of the bill -- including labor, Hispanic advocacy and religious groups -- also was planning a strong push to encourage lawmakers who support it not to back down.

"They're going to be targeted by a small but loud anti-reform minority," said Clarissa Martinez of the Coalition for Comprehensive Immigration Reform. "They must not buckle under the pressure."

New Poll Favors Guest Workers

A CBS/New York Times poll published Friday said that a large majority of Americans want illegal immigrants to be able to gain legal status. They also said they were in favor of a new guest worker program.

Related: Where Candidates Stand On Immigrantion

Sixty-six percent said they would favor a guest worker program, while 30 percent opposed such a program.

Sixty-two percent said that illegal immigrants should be allowed to apply for legal status, while 33 percent said they should be deported.

When asked if an illegal immigrant should be able to get a renewable visa if he or she pays a fine and passes a background check, 76 percent said "yes."

The nationwide telephone poll was conducted May 18 - 23 with 1,125 adults, and has a margin of sampling error of plus or minus three percentage points, the Times said.

The questioners did not ask respondents about the immigration bill in the Senate, but there were questions about its most significant provisions.

Senators Return In June

The Senate began considering the bill this week and will return to it in June.

Related: Where Candidates Stand On Immigrantion

The measure includes conservative-backed initiatives such as the worker verification program to prevent illegal immigrants from getting jobs and a new point system to prioritize skills and education over family in deciding who can immigrate in the future.

It also includes a long-sought liberal priority: granting legal status to the nation's estimated 12 million illegal immigrants. Conservatives view that as an unacceptable amnesty program.

President George W. Bush, who has made enactment of an immigration measure a top domestic priority, said he wasn't surprised at the tenor of the debate, and he urged lawmakers to look beyond it and deliver him a bill anyway.

"We've been through immigration debates in this country, and they can bring out the worst sometimes in people," Bush said. "But the question is, will members of Congress rise above politics?"