AUGUSTA – One of the state’s leading polling organizations will be closely gauging reaction to Thursday night’s presidential debate in an effort to make a conclusive determination on how Mainers will vote Nov. 2.

Patrick O. Murphy, president of Strategic Marketing Services of Portland, said Thursday that a recent survey of 400 Maine adults reflected a “statistical dead heat” between Republican President Bush and Massachusetts Sen. John F. Kerry, the Democratic nominee. Furthermore, the poll showed a growing number of former Kerry supporters switching to the undecided column – a development that Murphy said places the Democrat at a critical juncture as the three October debates get under way.

“Kerry must land an uppercut in these debates if he’s going to be able to get these undecided voters to go with him, and he hasn’t been able to do that so far,” Murphy said. “The Bush folks have done a hell of a good job in painting him into a corner.”

Although Murphy will release his full Fall 2004 Omnibus Poll next week, he gave political reporters a taste Thursday of his survey, which was conducted between Sept. 23 and Sept. 27.

Murphy said his “randomly selected, computer-generated, stratified” statewide sample of 400 Maine adults was administered only to people who are registered voters and who identified themselves as “likely” to vote in the November elections. All others were screened out.

He said the sample was stratified based on data obtained from the U.S. Census of Population and Housing and that the sample size had a statistical significance of plus or minus 4.9 percent at the 95 percent confidence level. In other words, if the poll were replicated using the same standards, 95 out of 100 times the results would remain within plus or minus 4.9 percent of the original sample.

Murphy said given the choice of Bush, Kerry or independent candidate Ralph Nader for president, 39 percent of the respondents indicated they would either vote or were leaning toward voting for Bush; 42.1 percent said they would either vote or were leaning toward voting for Kerry, and 4 percent would either vote or were leaning toward voting for Nader. Fifteen percent of respondents were undecided.

Although the poll shows Kerry with a 3.1 percent lead over Bush, the edge disappears when the poll’s margin of error is factored in. Even more troubling for the Kerry campaign was the way the Democrat’s numbers compared to earlier SMS polls. In March, Kerry charted the support of 50.8 percent of those surveyed. The number dropped to 43.5 percent in June and declined again this month. In contrast, Bush has gone from 37.8 percent in March to 41 percent in June to his current 39 percent favorable rating. Undecided voters moved during the same respective time periods from 7.5 percent to 11 percent to 15 percent, according to Murphy.

“This is a very tight race,” the pollster said.

Those surveyed also were asked whether Bush deserves re-election to the White House. Murphy said respondents were fairly evenly split, with 46 percent indicating the president did not deserve re-election and 43 percent saying he did. About 10 percent of respondents were undecided on the question.

Tipping the balance slightly for Bush is his “likability” quality among voters, which Murphy said some polls had placed as high as 50 percent. Kerry, he said, has rarely been able to break through the “high 30s.”

“There is a gap there and to a lot of voters, it’s a big issue because we tend to elect people we like more than whether we approve of their policies,” Murphy said.