Two experts on congressional politics say that Rep. Randy "Duke" Cunningham is in deep trouble with his Republican constituents, if the results of a poll released Thursday are on the mark.

Of those respondents who have followed the recent controversy involving the Escondido Republican, 76 percent said they thought the congressman broke the law or acted unethically when he sold his Del Mar Heights home to the president of a defense contractor in late 2003.

The poll was conducted by Survey USA of Verona, N.J., and commissioned by Channel 10 News, the local ABC network affiliate. The firm interviewed 700 people in Cunningham's 50th Congressional District on Wednesday. Included in the poll were 489 adults who said they were familiar with the Cunningham story, and they answered questions about their thoughts on the controversy surrounding the eight-term congressman and former Top Gun pilot.

The poll included 280 people who said they were Republicans and 182 who said they were Democrats. Those numbers are roughly proportionate to the number of registered Republicans and Democrats in the district, which has 158,904 Republicans and 105,701 Democrats.

Among the Republicans who said they were familiar with the story, 50 percent said they think Cunningham did something unethical, but not illegal; 29 percent of those Republicans said he broke the law. The margin of error for that question was 4.5 percent.

In another question, 43 percent of the Republicans who were aware of the Cunningham story said he should resign. The question had the same margin of error.

Of the Democrats who were aware of the Cunningham story, 32 percent said they believe he did something unethical, but not illegal; 49 percent said Cunningham broke the law.

On the question of whether Cunningham should resign, 63 percent of the Democrats said yes.

Two academics specializing in congressional races —— a Democrat and a Republican —— said Thursday that, based on the poll results, Cunningham's political future appears grim.

Cunningham came under fire last month, when news reports surfaced that he sold his house in 2003 to the founder of Washington-based MZM Inc., for $1.675 million —— a price that appears to be hundreds of thousands of dollars more than other similar homes in the area sold for at the time.

MZM has received millions of dollars in defense contracts in the last three years. Cunningham is a member of the powerful House Appropriations Subcommittee on Defense, which has influence over which companies get lucrative government contracts.

A federal grand jury investigation into the ties between the men is under way in San Diego.

Cunningham's 50th Congressional District stretches from Escondido and Carlsbad into portions of San Diego.

The poll asked three questions.

The first was: "Are you familiar with the story about Duke Cunningham selling his home to a military contractor?"

Seventy percent of those interviewed said they were familiar with the story. There was a plus-or-minus 3.5 percent margin of error, which means that, if the same sample was duplicated 20 times, in 19 cases the results would be that 66.5 to 73.5 percent had heard of the story.

The second question, with a plus-or-minus 4.5 percent margin of error, was: "Based on what you know right now, do you think Duke Cunningham broke the law? Do you think he did something unethical, but not illegal? Or do you think he did nothing wrong?"

According to the poll, 34 percent of those familiar with the story said they believed he broke the law; 42 percent said they believed he had done something unethical, but not illegal; 21 percent said he had done nothing wrong.

Party affiliation appeared to affect answers for many of those polled.

Of those who said they are Republicans, 29 percent said they believed he had broken the law, compared with 49 percent of Democrats. Meanwhile, 50 percent of Republicans said Cunningham had not acted ethically and had not broken the law, while 32 percent of Democrats shared that opinion. Twenty percent of Republicans and 16 percent of Democrats thought Cunningham had done nothing wrong.

The same type of party split seemed apparent in the third question, which had a plus-or-minus 4.5 percent margin of error: "Based on what you know right now, do you think Cunningham should remain in office? Or should he step down?" Fifty-three percent of Republicans and 25 percent of Democrats said he should remain in office. Meanwhile, 43 percent of Republicans thought he should step down, compared with 63 percent of Democrats. Twelve percent of Democrats and 4 percent of Republicans weren't sure.

A UC San Diego professor of political science and a registered Democrat, Gary Jacobson, said Thursday that the Republican numbers are the ones Cunningham should be most concerned with.

"If 79 percent of your base thinks you are either a crook or at least behaving unethically, then your constituency doesn't seem to be putting a lot of faith in you," said Jacobson, who specializes in congressional elections, Congress, public opinion and political parties.

Jacobson said that some of the difference in opinion in the poll seemed to split along party lines, but he's not surprised.

"Partisans give their own side the benefit of the doubt and withhold it from the other side," he said. The same thing occurred, in a much more dramatic fashion, after the Supreme Court decided that George Bush had won the state of Florida, and hence the presidency by the narrowest margin in history, Jacobson said.

"In December 2000, just after the election, 83 percent of Republicans said that Bush was the legitimate winner, and 22 percent of Democrats," Jacobson said.

Another academic, a Republican, shared Jacobson's pessimism about Cunningham's political future, based on the poll results.

"He is in a heap of trouble," said Jack Pitney, a former deputy director of research for the Republican National Committee and a professor of government at Claremont-McKenna College.

"It's not surprising that Democrats are against him, but a large fraction of Republicans are as well. He has to resolve these issues quickly or he will have a difficult time holding onto his job," Pitney said.

Contact staff writer William Finn Bennett at (760) 740-5426, or wbennett@nctimes.com.