By Edith Honan
NEW YORK (Reuters) - Democrats are bracing for an upset in a special election on Tuesday, in what some say could be a harbinger of the potential trouble Barack Obama could face in next year's presidential election.
Polls show Republican Bob Turner, a retired media executive, beating Democrat David Weprin, a state assemblyman, ahead of the U.S. House of Representatives election. The liberal stronghold has gone Democrat in every election since the 1920s, and Democrats outnumber Republicans 3 to 1.
"This district is loaded with the very people the Democrats need to win in big numbers," said Democratic political strategist Hank Sheinkopf.
The seat was held by Anthony Weiner, who resigned from Congress after admitting he used Twitter to send lewd pictures of himself to women.
Turner calls the race a referendum on Obama's handling of the economy.
"I'm hopeful we win it. I think it would be an unprecedented win given the demographic makeup of that district," U.S. House Republican Leader Eric Cantor told a news conference. "That district is not unlike the rest of the country; people are very unhappy with the economy right now."
Democrats have rushed in to help Weprin -- who some say is a lackluster campaigner from a family of New York politicians -- who has raised about three times as much money as Turner.
Former President Bill Clinton has recorded robo-calls urging Democrats to vote and U.S. Senator Charles Schumer has accompanied Weprin on the campaign trail.
Voters are frustrated more with Obama than the Republican-led House over the economy and the recent battle over a federal budget stalemate, said David Wasserman of the nonpartisan Cook Political Report, which tracks congressional races.
"This ought to be a wake-up call for Democrats," Wasserman said. "They need to pitch results."
A Siena Research Institute poll last week showed Turner ahead of Weprin by 6 percentage points, 50 percent to 44 percent. Public Policy Polling had Turner ahead 47 to 41 percent, and said he is winning nearly a third of Democrats and enjoying a huge lead with independents.
The New York race and a special election in Nevada in recent months show how traditional strongholds could be lost.
Democrats won a traditionally Republican House seat in a special election in upstate New York in May, largely because of voter backlash against a Republican-led plan to privatize Medicare, the popular healthcare program for the elderly.
With voters seemingly blaming Obama for the continued poor health of the economy, Republicans expect to easily hold a Nevada House seat and possibly pick up the one in New York.
Republicans control the House, 240-192 with three vacancies.
A Democratic aide, who asked not to be named, said the 9.1 percent national jobless rate and Obama's 43 percent approval rating made the New York race "closer than it should be."
Another potential factor in the race is the anger constituents and elected officials feel over Obama's stance on the state of Israel.
The district includes parts of Brooklyn and Queens and is heavily Jewish, but influential politicians like former New York mayor Ed Koch, a Democrat, endorsed Turner in protest of Obama's stance on Israel.
They say the president has not been sufficiently supportive of Israel and object to his call for Israeli-Palestinian negotiations to use the Jewish state's pre-1967 borders as a starting point.
(Additional reporting by Thomas Ferraro in Washington; editing by Mark Egan and Philip Barbara)