Voters go to the polls Tuesday in a special US congressional election for a heavily Democratic area of New York City where Republicans are hoping to score an upset and send a message to the White House.

The Ninth Congressional district in Queens and Brooklyn opened up in June when popular Democratic incumbent Anthony Weiner resigned over revelations that he was sending X-rated photos of himself to women he met online.

As if the clean-cut, married congressman's sex scandal was not embarrassing enough, Obama's party now risks the humiliation of losing a seat in a district where registered Democrats outnumber registered Republicans 3:1.

"Certainly the attitude and approval rating of the president is having a lot to do with this electorate and the election outcome tomorrow. I'm hopeful we win it," Republican House Majority Leader Eric Cantor said Monday.

The latest numbers from Public Policy Polling show Republican businessman Bob Turner leading veteran Democratic state and city legislator David Weprin by 47 to 41 percent.

Such a result would be seen as another dent in Obama's battered armor as the president gears up for reelection next year while grappling with deepening discontent over unemployment and his own job performance.

Analysts say the main reason for Weprin's struggle is his association with Obama, who has only a 45 percent national approval rating.

"If Turner wins on Tuesday it will be largely due to the incredible unpopularity of Barack Obama dragging his party down in the district," PPP said.

Cantor said the district was "not unlike the rest of the country: People are very unhappy with the economy right now and frankly, I would say, unhappy with the lack of leadership on the part of this White House."

Another big factor could be the outsized influence in this district of the Jewish vote. Turner has honed in on the large Orthodox Jewish community and could succeed in reversing the usual Democratic leanings of Jewish voters.

Conservative Jewish-Americans have long been suspicious about the water-tightness of Obama's support for Israel, so Turner has campaigned as a fervent pro-Israel partisan, as well as a social conservative, in contrast to Weprin, who voted as state assemblyman for gay marriage in New York.

Turner has won the support of a former New York mayor and lifelong Jewish Democrat, Ed Koch.

But Weprin is also fielding some big guns, with automated phone messages urging votes for him from former president Bill Clinton and current New York Governor Andrew Cuomo, USA Today reported.

Polls open at 6:00 am (1000 GMT) and close at 9:00 pm (0100 GMT Wednesday).