For as many headlines as Representative Anthony D. Weiner’s resignation generated, the race to replace him in the House has been a surprisingly under-the-radar campaign. A special election will take place in New York’s Ninth Congressional District on Sept. 13, however, and polls suggest it could be a competitive race.
But first, some background on how we forecast United States House races.
Our research has found that, while polls are certainly worth looking at in House races, they are much less accurate than polls for
contests like the United States Senate or governor. (This is liable to be even more true in special elections, when turnout is more erratic and therefore more difficult to model.) So, our forecasting methodology supplements the polling data with five additional pieces of information: the partisanship of the district, the national political environment, the results of the previous election in the district, fund-raising data and qualitative forecasts made by independent groups like the Cook Political Report. By applying this “kitchen sink” methodology, we were able to call about a dozen more United States House races correctly in 2010 than our competitors who relied on a technique based on polling alone.
Let’s look at each of these six factors in the context of the New York race, beginning with the polling data.
Polls
There have been four polls released in the contest, each of which had flaws.

The first poll, from Siena College, showed the Democrat, David I. Weprin, leading the Republican candidate, Bob Turner, by 6 percentage points, 48 to 42. However, that survey was conducted in early August and is now roughly a month old.
The campaigns of Mr. Weprin and Mr. Turner then released “dueling” internal polls, both of which were in the field at the same time. Mr. Turner’s poll showed him in a 42-to-42 tie with Mr. Weprin, while Mr. Weprin’s poll showed him ahead 47 to 39.
The split in the polls is not uncommon: our research suggests that internal polls released to the public by campaigns typically
exaggerate their candidate’s standing by a net of about 6 percentage points. Thus, the poll by Mr. Turner’s campaign, which showed the race tied, should be read as the equivalent of an independent poll that had shown him behind by 6 points. Likewise, the Democratic poll, which had Mr. Weprin with an 8-point edge, is tantamount to an independent poll that had given him just a 2-point lead.
That is right. Given the bias inherent in these types of surveys, in some ways a Democratic internal poll showing the race within single digits is a more impressive result for Mr. Turner than his own poll, which had showed the race tied. But both polls are in the same range as one another.
Finally, a poll was released by Magellan Strategies showing Mr. Turner, the Republican, actually ahead in the race 45 to 40.
Magellan Strategies is a Republican-affiliated pollster, but the firm paid for this particular poll, which our research suggests leads to less bias than polls that are explicitly sponsored by a campaign or partisan group. In fact, although Magellan is a relatively new pollster, my impression based on the surveys they released in 2010 is that they play it pretty up the middle.
With that said, there is room to critique the poll: it was an automated survey conducted within a single 24-hour period, and it did not identify the additional ballot lines that the candidates are listed under, something that a pollster probably should do given New York’s fusion balloting. (Mr. Turner is also the nominee of the Conservative Party of New York, while Mr. Weprin has the endorsements of the Independence Party of New York and the Working Families’ Party.)
There are likely to be additional polls released in the race, like an updated round of polling from Siena College. For the time being, however, they look like something of a wash, so we should turn to the other factors.
District Partisanship
The Ninth District, which stretches over portions of Brooklyn and Queens, includes neighborhoods like Sheepshead Bay, Kew Gardens and Rockaway Beach, and might once have been described as an “ethnic white” district. It includes substantial numbers of Orthodox Jewish voters as well as other groups like Italian-Americans and some Russian-Americans. About 30 percent of the district’s population, meanwhile, is nonwhite — mainly Asian and Hispanic rather than African-American.
The district’s partisanship is harder to benchmark. The indicator that our forecasting model uses is the district’s presidential vote, and by that metric the district is Democratic-leaning, but only slightly so. Barack Obama received 55 percent of the vote there in 2008, barely better than the 53 percent he received nationwide. But, Al Gore had beaten George W. Bush in the district by 67-to-30 margin in 2000, meaning that the district has had among the largest shifts toward Republicans of any in the country.

On the other hand, the district has not shown very much of a shift in its partisan registration, with Democrats retaining a very substantial advantage. About 57 percent of voters there are still registered as Democrats, versus 18 percent Republican.

What we can say about the district is that it does not seem to be very fond of Mr. Obama: the Siena poll found that a slight majority of voters there have a negative impression of the president. It is more difficult to know how this would translate into a race for Congress.
Past U.S. House Results
Mr. Weiner never had much trouble carrying the district, however, winning by 22 points there in 2010 against Mr. Turner despite a poor overall political climate for Democrats. And Mr. Weiner did not draw a Republican challenger at all in 2006 or 2008.
However, because Mr. Weiner is no longer on the ballot, and because the magnitude of the incumbency advantage varies substantially from district to district, this is of marginal utility for forecasting purposes.
National Political Environment
Our preferred diagnostic for the national partisan environment is a composite of generic ballot polls. We noted in this space previously that the Gallup generic ballot poll had shown a substantial shift toward Democrats, giving them a 7-point advantage. Other generic ballot polls have not necessarily followed suit, however, and are all over the map.
What we can probably say is that the overall partisan climate is not as bad for Democrats as it was in 2010 — nor as good for them as it was in 2006 or 2008. But beyond that, it is difficult to pinpoint.
Nor is it clear how the anti-incumbent mood will manifest itself in a district that usually votes Democratic, which had a Democratic congressman before, and which is lukewarm at best on the Democratic president, but which is also not in alignment with the conservative fiscal policies of the Republican majority in the House, from which Mr. Turner has made some effort to distance himself.
Fund-raising
Finally, something where one of the candidates has a relatively unambiguous advantage. According to disclosure reports filed with the Federal Election Commission, Mr. Weprin had brought in about $450,000 as of Aug. 24, as compared with about $140,000 for Mr. Turner.
In particular, our forecasting model looks at individual contributions, ignoring donations made by the parties or by political action committees. Mr. Weprin has an edge there, too, with $290,000 in individual contributions versus about $130,000 for Mr. Turner.
Both figures, frankly, are a bit underwhelming — especially considering that candidates for office in New York City need to hit a pretty high fund-raising threshold before they can make much headway from television and radio advertising. But Mr. Weprin’s fund-raising total is closer to being acceptable.
Each candidate’s fund-raising is heavily weighted toward voters from New York State, so there is not much sign of interest from partisans elsewhere in the country.
Expert Forecasts
One of the most important indicators that our model uses are characterizations of the race made by independent groups like the Cook Political Report and CQ Politics — which add substantial value relative to polls and other objective evidence. So far, however, these organizations have been reluctant to provide a diagnosis of the race, although David Wasserman, an editor for the Cook Political Report, described the race as somewhere between a tossup and “leaning” Democratic.
The broader lesson is that “intangible” factors like candidate quality matter in United States House races. (Groups like Cook Political conduct interviews with dozens and dozens of potential candidates in advance of each election cycle.)
The Magellan poll suggests that the Republican, Mr. Turner, has a stronger favorability rating and is doing several percentage points better than a “generic” Republican would in the district. On the other hand, he has never held elected office before, whereas Mr. Weprin has, having served in the New York State Assembly as well as on the New York City Council.
The Big Picture
If I were a Republican, here is what I would be worried about. Polls show a tight race, but Mr. Weprin has a reasonably significant fund-raising advantage and has run winning campaigns before in New York City. Mr. Turner has not. Also, New York is run by Democratic politicians, and the city has a substantial union presence, which could bolster Mr. Weprin’s turnout, particularly given that the majority of voters in the district are registered Democrats. And with neither campaign having been able to afford a substantial presence on the airwaves, the “ground game” in this election is likely to be important.
For Democrats, meanwhile, nervousness should revolve around the fact that Mr. Obama is a potential liability given this district’s tepid reviews of him, and its trend toward greater Republican voting in presidential elections. And if Mr. Weprin is closer to being the de facto incumbent, that might not be so much of an advantage in the current political climate. In addition, Mr. Turner has tried to localize the race, for instance by critiquing Mr. Weprin’s support of the so-called “Ground Zero Mosque,” an issue which could be pertinent in an election will take place just two days after the 10th anniversary of the Sept. 11 attacks.
Over all, Mr. Weprin’s advantages are more tangible, which is why I would consider him a modest favorite given the ambiguity in the polling.
But a victory by Mr. Turner would hardly be surprising. I always caution against drawing national implications from special election results, and would certainly do so here given the idiosyncrasies of the district. But it would represent a nice little notch in Republicans’ belts and a troubling data point for Democrats.