A new Siena Research poll suggests that Republicans could win the Sept. 13 special election in former Rep. Anthony Weiner’s New York City district, a result that would be embarrassing for Democrats and would likely complicate redistricting plans.

The finds Republican businessman Robert Turner in striking distance of Democratic state Assemblyman David Weprin, 42 percent to 48 percent, suggesting a possible upset.

And with the election a month away, voters’ minds are surprisingly set. Only 15 percent of respondents said they were likely or very likely to change their minds.

There’s a borough divide going on here. Turner leads by six points in Brooklyn, Weiner’s home base. Weprin leads by 10 points in Queens, where he and his family are very well known. Brooklyn comprises 30 percent of the district; the rest is in Queens.

Turner ran against Weiner in 2010 and surpassed expectations by garnering 40 percent of the vote in the heavily Democratic district. This time around, he got a high-profile boost from former mayor Ed Koch (D), who cited Turner’s support for Israel.

While 38 percent of poll respondents’ said Koch’s endorsement would make them more likely to vote for a candidate — giving the ex-mayor more sway than President Obama but less than Sen. Charles Schumer — Jewish voters still sided heavily with Weprin, who is Jewish.

As we’ve written many times before, special elections rarely have larger meaning — the circumstances are just too particular to have much weight beyond the election itself. But a Democratic loss here would be disheartening for the party.

A Republican win would also complicate redistricting plans. New York is losing two seats, and given split control of the legislature each party is likely to give up one. Conventional wisdom has it that Democrats will eliminate Weiner’s district, avoiding a tough decision. If they lose this seat, they will have to look elsewhere.

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